diff --git a/src/test/java/org/hisp/dhis/rules/ConstantsValueTest.java b/src/test/java/org/hisp/dhis/rules/ConstantsValueTest.java
index 72b69f68..238ed3f4 100644
--- a/src/test/java/org/hisp/dhis/rules/ConstantsValueTest.java
+++ b/src/test/java/org/hisp/dhis/rules/ConstantsValueTest.java
@@ -44,7 +44,6 @@
 import org.junit.runners.JUnit4;
 
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.Date;
 import java.util.HashMap;
 import java.util.List;
@@ -110,7 +109,7 @@ public void assignValue()
         org.hisp.dhis.rules.models.Rule rule2 = org.hisp.dhis.rules.models.Rule
             .create( null, 1, "#{test_attribute} > 3", List.of(action), "test_program_rule2", "" );
 
-        RuleEngine.Builder ruleEngineBuilder = getRuleEngine( Arrays.asList( rule, rule2 ),
+        RuleEngine.Builder ruleEngineBuilder = getRuleEngine( List.of( rule, rule2 ),
             new HashMap<>() );
 
         RuleEnrollment enrollment = RuleEnrollment.builder()
@@ -145,7 +144,7 @@ public void assignValueThroughVariable()
         org.hisp.dhis.rules.models.Rule rule2 = org.hisp.dhis.rules.models.Rule
             .create( null, 1, "#{test_attribute} > 3", List.of(action), "test_program_rule2", "" );
 
-        RuleEngine.Builder ruleEngineBuilder = getRuleEngine( Arrays.asList( rule, rule2 ),
+        RuleEngine.Builder ruleEngineBuilder = getRuleEngine( List.of( rule, rule2 ),
             new HashMap<>() );
 
         RuleEnrollment enrollment = RuleEnrollment.builder()
diff --git a/src/test/java/org/hisp/dhis/rules/ProgramRuleVariableTest.java b/src/test/java/org/hisp/dhis/rules/ProgramRuleVariableTest.java
index d4e2eac5..f5ed1491 100644
--- a/src/test/java/org/hisp/dhis/rules/ProgramRuleVariableTest.java
+++ b/src/test/java/org/hisp/dhis/rules/ProgramRuleVariableTest.java
@@ -37,7 +37,6 @@
 import org.hisp.dhis.rules.models.RuleEnrollment;
 import org.hisp.dhis.rules.models.RuleEvent;
 import org.hisp.dhis.rules.models.TriggerEnvironment;
-import org.junit.Assert;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
diff --git a/src/test/java/org/hisp/dhis/rules/RuleEngineContextTest.java b/src/test/java/org/hisp/dhis/rules/RuleEngineContextTest.java
index 66a3c594..650951a9 100644
--- a/src/test/java/org/hisp/dhis/rules/RuleEngineContextTest.java
+++ b/src/test/java/org/hisp/dhis/rules/RuleEngineContextTest.java
@@ -8,7 +8,6 @@
 import org.junit.runners.JUnit4;
 
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -48,7 +47,7 @@ public void builderShouldThrowOnNullRulesList()
     @Test
     public void builderShouldContainImmutableCopyOfRules()
     {
-        List<String> members = Arrays.asList( "one", "two" );
+        List<String> members = List.of( "one", "two" );
         Map<String, List<String>> supplementaryData = new HashMap<>();
         supplementaryData.put( "text-key", members );
 
diff --git a/src/test/java/org/hisp/dhis/rules/RuleEngineEffectTypesTest.java b/src/test/java/org/hisp/dhis/rules/RuleEngineEffectTypesTest.java
index d6f70ef3..93916176 100644
--- a/src/test/java/org/hisp/dhis/rules/RuleEngineEffectTypesTest.java
+++ b/src/test/java/org/hisp/dhis/rules/RuleEngineEffectTypesTest.java
@@ -4,15 +4,15 @@
 import org.hisp.dhis.rules.models.RuleAction;
 import org.hisp.dhis.rules.models.RuleActionAssign;
 import org.hisp.dhis.rules.models.RuleActionCreateEvent;
-import org.hisp.dhis.rules.models.RuleActionMessage;
-import org.hisp.dhis.rules.models.RuleActionText;
 import org.hisp.dhis.rules.models.RuleActionHideField;
 import org.hisp.dhis.rules.models.RuleActionHideOption;
 import org.hisp.dhis.rules.models.RuleActionHideOptionGroup;
 import org.hisp.dhis.rules.models.RuleActionHideProgramStage;
 import org.hisp.dhis.rules.models.RuleActionHideSection;
+import org.hisp.dhis.rules.models.RuleActionMessage;
 import org.hisp.dhis.rules.models.RuleActionScheduleMessage;
 import org.hisp.dhis.rules.models.RuleActionSetMandatoryField;
+import org.hisp.dhis.rules.models.RuleActionText;
 import org.hisp.dhis.rules.models.RuleDataValue;
 import org.hisp.dhis.rules.models.RuleEffect;
 import org.hisp.dhis.rules.models.RuleEffects;
diff --git a/src/test/java/org/hisp/dhis/rules/RuleEngineFunctionTest.java b/src/test/java/org/hisp/dhis/rules/RuleEngineFunctionTest.java
index f034c1db..5ac9f5eb 100644
--- a/src/test/java/org/hisp/dhis/rules/RuleEngineFunctionTest.java
+++ b/src/test/java/org/hisp/dhis/rules/RuleEngineFunctionTest.java
@@ -21,7 +21,6 @@
 import java.time.LocalDate;
 import java.time.ZoneOffset;
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.Collections;
 import java.util.Date;
 import java.util.HashMap;
@@ -147,7 +146,7 @@ public void optionSetNameShouldBeUsed()
         Option option1 = new Option("name1", "code1");
         Option option2 = new Option("name2", "code2");
 
-        List<Option> options = Arrays.asList( option1, option2 );
+        List<Option> options = List.of( option1, option2 );
 
         RuleAction ruleAction = RuleActionText.createForFeedback(
                 "test_action_content", "#{test_variable}" );
@@ -174,7 +173,7 @@ public void optionSetCodeShouldBeUsed()
         Option option1 = new Option("name1", "code1");
         Option option2 = new Option("name2", "code2");
 
-        List<Option> options = Arrays.asList( option1, option2 );
+        List<Option> options = List.of( option1, option2 );
 
         RuleAction ruleAction = RuleActionText.createForFeedback(
                 "test_action_content", "#{test_variable}" );
@@ -273,10 +272,10 @@ public void evaluateDaysBetweenMustReturnCorrectDiff()
             "test_var_two", "test_data_element_two", RuleValueType.TEXT, true, new ArrayList<>());
         Rule rule = Rule.create( null, null, "true", List.of(ruleAction), "", "" );
 
-        RuleEngine ruleEngine = getRuleEngine( rule, Arrays.asList( ruleVariableOne, ruleVariableTwo ) );
+        RuleEngine ruleEngine = getRuleEngine( rule, List.of( ruleVariableOne, ruleVariableTwo ) );
 
         RuleEvent ruleEvent = RuleEvent.create( "test_event", "test_program_stage",
-            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_one", "2017-01-01" ),
                 RuleDataValue
                     .create( new Date(), "test_program_stage", "test_data_element_two", "2017-02-01" ) ), "", null);
@@ -299,10 +298,10 @@ public void evaluateDaysBetweenWithSingleQuotedDateMustReturnCorrectDiff()
             "test_var_two", "test_data_element_two", RuleValueType.TEXT, true, new ArrayList<>());
         Rule rule = Rule.create( null, null, "true", List.of(ruleAction), "", "" );
 
-        RuleEngine ruleEngine = getRuleEngine( rule, Arrays.asList( ruleVariableOne, ruleVariableTwo ) );
+        RuleEngine ruleEngine = getRuleEngine( rule, List.of( ruleVariableOne, ruleVariableTwo ) );
 
         RuleEvent ruleEvent = RuleEvent.create( "test_event", "test_program_stage",
-            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_one", "2017-01-01" ),
                 RuleDataValue
                     .create( new Date(), "test_program_stage", "test_data_element_two", "2017-02-01" ) ), "", null);
@@ -317,7 +316,7 @@ RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
     public void evaluateD2InOrgUnitGroup()
         throws Exception
     {
-        List<String> members = Arrays.asList( "location1", "location2" );
+        List<String> members = List.of( "location1", "location2" );
 
         Map<String, List<String>> supplementaryData = new HashMap<>();
         supplementaryData.put( "OU_GROUP_ID", members );
@@ -355,7 +354,7 @@ RuleEvent.Status.ACTIVE, new Date(), new Date(), "location1", null, List.of(
     public void evaluateD2InOrgUnitGroupWithStringValue()
         throws Exception
     {
-        List<String> members = Arrays.asList( "location1", "location2" );
+        List<String> members = List.of( "location1", "location2" );
 
         Map<String, List<String>> supplementaryData = new HashMap<>();
         supplementaryData.put( "OU_GROUP_ID", members );
@@ -392,7 +391,7 @@ RuleEvent.Status.ACTIVE, new Date(), new Date(), "location1", null, List.of(
     public void evaluateD2HasUserRole()
         throws Exception
     {
-        List<String> roles = Arrays.asList( "role1", "role2" );
+        List<String> roles = List.of( "role1", "role2" );
 
         Map<String, List<String>> supplementaryData = new HashMap<>();
         supplementaryData.put( "USER", roles );
@@ -429,7 +428,7 @@ RuleEvent.Status.ACTIVE, new Date(), new Date(), "location1", null, List.of(
     public void evaluateD2HasUserRoleWithStringValue()
         throws Exception
     {
-        List<String> roles = Arrays.asList( "role1", "role2" );
+        List<String> roles = List.of( "role1", "role2" );
 
         Map<String, List<String>> supplementaryData = new HashMap<>();
         supplementaryData.put( "USER", roles );
@@ -473,10 +472,10 @@ public void evaluateD2AddDays()
             "test_var_two", "test_data_element_two", RuleValueType.TEXT, true, new ArrayList<>());
         Rule rule = Rule.create( null, null, "true", List.of(ruleAction), "", "" );
 
-        RuleEngine ruleEngine = getRuleEngine( rule, Arrays.asList( ruleVariableOne, ruleVariableTwo ) );
+        RuleEngine ruleEngine = getRuleEngine( rule, List.of( ruleVariableOne, ruleVariableTwo ) );
 
         RuleEvent ruleEvent = RuleEvent.create( "test_event", "test_program_stage",
-            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_one", "2017-01-01" ),
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_two", "2" ) ), "", null);
         List<RuleEffect> ruleEffects = ruleEngine.evaluate( ruleEvent ).call();
@@ -486,7 +485,7 @@ RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
         assertEquals( ruleEffects.get( 0 ).data() , "2017-01-03" );
 
         RuleEvent ruleEvent2 = RuleEvent.create( "test_event", "test_program_stage",
-            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_one", "2017-01-03" ),
                 RuleDataValue
                     .create( new Date(), "test_program_stage", "test_data_element_two", "-2" ) ), "", null);
@@ -520,7 +519,7 @@ RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
             RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                         RuleDataValue.create(new Date(), "test_program_stage", "test_data_element_one", "condition")), "", null);
 
-        ruleEngineBuilder.events( Arrays.asList( ruleEvent2, ruleEvent3 ) );
+        ruleEngineBuilder.events( List.of( ruleEvent2, ruleEvent3 ) );
 
         List<RuleEffect> ruleEffects = ruleEngineBuilder.build().evaluate( ruleEvent ).call();
 
@@ -553,7 +552,7 @@ RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
             RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                         RuleDataValue.create(new Date(), "test_program_stage", "test_data_element_one", "condition")), "", null);
 
-        ruleEngineBuilder.events( Arrays.asList( ruleEvent2, ruleEvent3 ) );
+        ruleEngineBuilder.events( List.of( ruleEvent2, ruleEvent3 ) );
 
         List<RuleEffect> ruleEffects = ruleEngineBuilder.build().evaluate( ruleEvent ).call();
 
@@ -592,7 +591,7 @@ RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
             RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                         RuleDataValue.create(new Date(), "test_program_stage", "test_data_element_two", "condition")), "", null);
 
-        ruleEngineBuilder.events( Arrays.asList( ruleEvent2, ruleEvent3, ruleEvent4 ) );
+        ruleEngineBuilder.events( List.of( ruleEvent2, ruleEvent3, ruleEvent4 ) );
 
         List<RuleEffect> ruleEffects = ruleEngineBuilder.build().evaluate( ruleEvent ).call();
 
@@ -690,7 +689,7 @@ RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
             RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                         RuleDataValue.create(new Date(), "test_program_stage", "test_data_element_two", "condition")), "", null);
 
-        ruleEngineBuilder.events( Arrays.asList( ruleEvent2, ruleEvent3, ruleEvent4 ) );
+        ruleEngineBuilder.events( List.of( ruleEvent2, ruleEvent3, ruleEvent4 ) );
 
         List<RuleEffect> ruleEffects = ruleEngineBuilder.build().evaluate( ruleEvent ).call();
 
@@ -784,10 +783,10 @@ public void evaluateD2WeeksBetween()
         Rule rule = Rule.create( null, null, "true", List.of(ruleAction), "", "" );
 
         RuleEngine.Builder ruleEngineBuilder = getRuleEngineBuilder( rule,
-            Arrays.asList( ruleVariableOne, ruleVariableTwo ) );
+            List.of( ruleVariableOne, ruleVariableTwo ) );
 
         RuleEvent ruleEvent = RuleEvent.create( "test_event", "test_program_stage",
-            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_one", "2018-01-01" ),
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_two", "2018-02-01" ) ), "", null);
 
@@ -811,10 +810,10 @@ public void evaluateD2MonthsBetween()
         Rule rule = Rule.create( null, null, "true", List.of(ruleAction), "", "" );
 
         RuleEngine.Builder ruleEngineBuilder = getRuleEngineBuilder( rule,
-            Arrays.asList( ruleVariableOne, ruleVariableTwo ) );
+            List.of( ruleVariableOne, ruleVariableTwo ) );
 
         RuleEvent ruleEvent = RuleEvent.create( "test_event", "test_program_stage",
-            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_one", "2018-01-01" ),
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_two", "2018-09-01" ) ), "", null);
 
@@ -840,10 +839,10 @@ public void evaluateD2YearsBetween()
                 "" );
 
         RuleEngine.Builder ruleEngineBuilder = getRuleEngineBuilder( rule,
-            Arrays.asList( ruleVariableOne, ruleVariableTwo ) );
+            List.of( ruleVariableOne, ruleVariableTwo ) );
 
         RuleEvent ruleEvent = RuleEvent.create( "test_event", "test_program_stage",
-            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_one", "2016-01-01" ),
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_two", "2018-09-01" ) ), "", null);
 
@@ -869,7 +868,7 @@ public void evaluateD2Zpvc()
         Rule rule = Rule.create( null, null, "true", Collections.singletonList(ruleAction), "", "" );
 
         RuleEngine.Builder ruleEngineBuilder = getRuleEngineBuilder( rule,
-            Arrays.asList( ruleVariableOne, ruleVariableTwo ) );
+            List.of( ruleVariableOne, ruleVariableTwo ) );
 
         RuleEvent ruleEvent = RuleEvent.create( "test_event", "test_program_stage",
             RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(), "", null);
@@ -948,7 +947,7 @@ RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
             RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                         RuleDataValue.create(new Date(), "test_program_stage", "test_data_element_one", "-3")), "", null);
 
-        List<RuleEffect> ruleEffects = ruleEngineBuilder.events( Arrays.asList( ruleEvent1, ruleEvent2 ) ).build()
+        List<RuleEffect> ruleEffects = ruleEngineBuilder.events( List.of( ruleEvent1, ruleEvent2 ) ).build()
             .evaluate( ruleEvent ).call();
 
         assertEquals( 1 , ruleEffects.size() );
@@ -982,7 +981,7 @@ RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
             RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                         RuleDataValue.create(new Date(), "test_program_stage", "test_data_element_one", "-3")), "", null);
 
-        List<RuleEffect> ruleEffects = ruleEngineBuilder.events( Arrays.asList( ruleEvent1, ruleEvent2 ) ).build()
+        List<RuleEffect> ruleEffects = ruleEngineBuilder.events( List.of( ruleEvent1, ruleEvent2 ) ).build()
             .evaluate( ruleEvent ).call();
 
         assertEquals( 1 , ruleEffects.size() );
@@ -1165,10 +1164,10 @@ public void evaluateNestedFunctionCalls()
         Rule rule = Rule.create( null, null, "true", List.of(ruleAction), "", "" );
 
         RuleEngine ruleEngine = getRuleEngine( rule,
-            Arrays.asList( ruleVariableOne, ruleVariableTwo, ruleVariableThree ) );
+            List.of( ruleVariableOne, ruleVariableTwo, ruleVariableThree ) );
 
         RuleEvent ruleEvent = RuleEvent.create( "test_event", "test_program_stage",
-            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_one", "19.9" ),
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_two", "0.9" ),
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_three", "10.6" ) ), "", null);
@@ -1196,10 +1195,10 @@ public void evaluateD2ZScoreWFA()
                 "", "" );
 
         RuleEngine.Builder ruleEngineBuilder = getRuleEngineBuilder( rule,
-            Arrays.asList( ruleVariableOne, ruleVariableTwo ) );
+            List.of( ruleVariableOne, ruleVariableTwo ) );
 
         RuleEvent ruleEvent = RuleEvent.create( "test_event", "test_program_stage",
-            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_one", "4.5" ),
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_two", "male" ) ), "", null);
 
@@ -1226,10 +1225,10 @@ public void evaluateD2ZScoreHFAGirl()
                 "", "" );
 
         RuleEngine.Builder ruleEngineBuilder = getRuleEngineBuilder( rule,
-            Arrays.asList( ruleVariableOne, ruleVariableTwo ) );
+            List.of( ruleVariableOne, ruleVariableTwo ) );
 
         RuleEvent ruleEvent = RuleEvent.create( "test_event", "test_program_stage",
-            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_one", "66.3" ),
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_two", "1" ) ), "", null);
 
@@ -1256,10 +1255,10 @@ public void evaluateD2ZScoreHFABoy()
                 "", "" );
 
         RuleEngine.Builder ruleEngineBuilder = getRuleEngineBuilder( rule,
-            Arrays.asList( ruleVariableOne, ruleVariableTwo ) );
+            List.of( ruleVariableOne, ruleVariableTwo ) );
 
         RuleEvent ruleEvent = RuleEvent.create( "test_event", "test_program_stage",
-            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_one", "68.7" ),
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_two", "male" ) ), "", null);
 
@@ -1286,10 +1285,10 @@ public void evaluateD2ZScoreWFHBoy()
                 "", "" );
 
         RuleEngine.Builder ruleEngineBuilder = getRuleEngineBuilder( rule,
-            Arrays.asList( ruleVariableOne, ruleVariableTwo ) );
+            List.of( ruleVariableOne, ruleVariableTwo ) );
 
         RuleEvent ruleEvent = RuleEvent.create( "test_event", "test_program_stage",
-            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_one", "3" ),
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_two", "male" ) ), "", null);
 
@@ -1316,10 +1315,10 @@ public void evaluateD2ZScoreWFHGirl()
                 "", "" );
 
         RuleEngine.Builder ruleEngineBuilder = getRuleEngineBuilder( rule,
-            Arrays.asList( ruleVariableOne, ruleVariableTwo ) );
+            List.of( ruleVariableOne, ruleVariableTwo ) );
 
         RuleEvent ruleEvent = RuleEvent.create( "test_event", "test_program_stage",
-            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_one", "12.5" ),
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_two", "1" ) ), "", null);
 
@@ -1345,24 +1344,24 @@ public void evaluateD2MaxValue()
             .create( null, null, "d2:maxValue(#{test_var_one}) == 8.0", List.of(ruleAction), "", "" );
 
         RuleEngine.Builder ruleEngineBuilder = getRuleEngineBuilder( rule,
-            Arrays.asList( ruleVariableOne, ruleVariableTwo ) );
+            List.of( ruleVariableOne, ruleVariableTwo ) );
 
         RuleEvent ruleEvent1 = RuleEvent.create( "test_event1", "test_program_stage1",
-            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_one", "5" ),
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_two", "male" ) ), "", null);
 
         RuleEvent ruleEvent2 = RuleEvent.create( "test_event2", "test_program_stage2",
-            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_one", "7" ),
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_two", "male" ) ), "", null);
 
         RuleEvent ruleEvent3 = RuleEvent.create( "test_event3", "test_program_stage3",
-            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_one", "8" ),
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_two", "male" ) ), "", null);
 
-        List<RuleEffect> ruleEffects = ruleEngineBuilder.events( Arrays.asList( ruleEvent1, ruleEvent2 ) ).build()
+        List<RuleEffect> ruleEffects = ruleEngineBuilder.events( List.of( ruleEvent1, ruleEvent2 ) ).build()
             .evaluate( ruleEvent3 ).call();
 
         assertEquals( 1 , ruleEffects.size() );
@@ -1386,24 +1385,24 @@ public void evaluateD2MaxValueWithStringValue()
             .create( null, null, "d2:maxValue('test_var_one') == 8.0", List.of(ruleAction), "", "" );
 
         RuleEngine.Builder ruleEngineBuilder = getRuleEngineBuilder( rule,
-            Arrays.asList( ruleVariableOne, ruleVariableTwo ) );
+            List.of( ruleVariableOne, ruleVariableTwo ) );
 
         RuleEvent ruleEvent1 = RuleEvent.create( "test_event1", "test_program_stage1",
-            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_one", "5" ),
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_two", "male" ) ), "", null);
 
         RuleEvent ruleEvent2 = RuleEvent.create( "test_event2", "test_program_stage2",
-            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_one", "7" ),
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_two", "male" ) ), "", null);
 
         RuleEvent ruleEvent3 = RuleEvent.create( "test_event3", "test_program_stage3",
-            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_one", "8" ),
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_two", "male" ) ), "", null);
 
-        List<RuleEffect> ruleEffects = ruleEngineBuilder.events( Arrays.asList( ruleEvent1, ruleEvent2 ) ).build()
+        List<RuleEffect> ruleEffects = ruleEngineBuilder.events( List.of( ruleEvent1, ruleEvent2 ) ).build()
             .evaluate( ruleEvent3 ).call();
 
         assertEquals( 1 , ruleEffects.size() );
@@ -1425,24 +1424,24 @@ public void testMinValue()
         Rule rule = Rule.create( null, null, "true", List.of(ruleAction), "", "" );
 
         RuleEngine.Builder ruleEngineBuilder = getRuleEngineBuilder( rule,
-            Arrays.asList( ruleVariableOne, ruleVariableTwo ) );
+            List.of( ruleVariableOne, ruleVariableTwo ) );
 
         RuleEvent ruleEvent1 = RuleEvent.create( "test_event1", "test_program_stage1",
-            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_one", "5" ),
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_two", "male" ) ), "", null);
 
         RuleEvent ruleEvent2 = RuleEvent.create( "test_event2", "test_program_stage2",
-            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_one", "7" ),
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_two", "male" ) ), "", null);
 
         RuleEvent ruleEvent3 = RuleEvent.create( "test_event3", "test_program_stage3",
-            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_one", "8" ),
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_two", "male" ) ), "", null);
 
-        List<RuleEffect> ruleEffects = ruleEngineBuilder.events( Arrays.asList( ruleEvent1, ruleEvent2 ) ).build()
+        List<RuleEffect> ruleEffects = ruleEngineBuilder.events( List.of( ruleEvent1, ruleEvent2 ) ).build()
             .evaluate( ruleEvent3 ).call();
 
         assertEquals( 1 , ruleEffects.size() );
@@ -1465,24 +1464,24 @@ public void testMinValueWithStringValue()
         Rule rule = Rule.create( null, null, "true", List.of(ruleAction), "", "" );
 
         RuleEngine.Builder ruleEngineBuilder = getRuleEngineBuilder( rule,
-            Arrays.asList( ruleVariableOne, ruleVariableTwo ) );
+            List.of( ruleVariableOne, ruleVariableTwo ) );
 
         RuleEvent ruleEvent1 = RuleEvent.create( "test_event1", "test_program_stage1",
-            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_one", "5" ),
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_two", "male" ) ), "", null);
 
         RuleEvent ruleEvent2 = RuleEvent.create( "test_event2", "test_program_stage2",
-            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_one", "7" ),
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_two", "male" ) ), "", null);
 
         RuleEvent ruleEvent3 = RuleEvent.create( "test_event3", "test_program_stage3",
-            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_one", "8" ),
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_two", "male" ) ), "", null);
 
-        List<RuleEffect> ruleEffects = ruleEngineBuilder.events( Arrays.asList( ruleEvent1, ruleEvent2 ) ).build()
+        List<RuleEffect> ruleEffects = ruleEngineBuilder.events( List.of( ruleEvent1, ruleEvent2 ) ).build()
             .evaluate( ruleEvent3 ).call();
 
         assertEquals( 1 , ruleEffects.size() );
@@ -1526,7 +1525,7 @@ RuleEvent.Status.ACTIVE, yesterday, new Date(), "", null, List.of(
                         RuleDataValue.create(dayAfterTomorrow, "test_program_stage3", "test_data_element_one", "value3")),
             "", null);
 
-        List<RuleEffect> ruleEffects = ruleEngineBuilder.events( Arrays.asList( ruleEvent1, ruleEvent2 ) ).build()
+        List<RuleEffect> ruleEffects = ruleEngineBuilder.events( List.of( ruleEvent1, ruleEvent2 ) ).build()
             .evaluate( ruleEvent3 ).call();
 
         assertEquals( 1 , ruleEffects.size() );
diff --git a/src/test/java/org/hisp/dhis/rules/RuleEngineVariableNameTest.java b/src/test/java/org/hisp/dhis/rules/RuleEngineVariableNameTest.java
index 1a2ed2f9..877ed864 100644
--- a/src/test/java/org/hisp/dhis/rules/RuleEngineVariableNameTest.java
+++ b/src/test/java/org/hisp/dhis/rules/RuleEngineVariableNameTest.java
@@ -93,7 +93,7 @@ public void evaluateD2Round()
             ruleVariables );
 
         RuleEvent ruleEvent = RuleEvent.create( "test_event", "test_program_stage",
-            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element1", "2.6" ),
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element2", "2.6" ),
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element3", "2.6" ),
@@ -198,7 +198,7 @@ RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
             RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                         RuleDataValue.create(new Date(), "test_program_stage", "test_data_element_one", "condition")), "", null);
 
-        ruleEngineBuilder.events( Arrays.asList( ruleEvent2, ruleEvent3 ) );
+        ruleEngineBuilder.events( List.of( ruleEvent2, ruleEvent3 ) );
 
         List<RuleEffect> ruleEffects = ruleEngineBuilder.build().evaluate( ruleEvent ).call();
 
@@ -230,7 +230,7 @@ RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
             RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                         RuleDataValue.create(new Date(), "test_program_stage", "test_data_element_one", "condition")), "", null);
 
-        ruleEngineBuilder.events( Arrays.asList( ruleEvent2, ruleEvent3 ) );
+        ruleEngineBuilder.events( List.of( ruleEvent2, ruleEvent3 ) );
 
         List<RuleEffect> ruleEffects = ruleEngineBuilder.build().evaluate( ruleEvent ).call();
 
@@ -269,7 +269,7 @@ RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
             RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                         RuleDataValue.create(new Date(), "test_program_stage", "test_data_element_two", "condition")), "", null);
 
-        ruleEngineBuilder.events( Arrays.asList( ruleEvent2, ruleEvent3, ruleEvent4 ) );
+        ruleEngineBuilder.events( List.of( ruleEvent2, ruleEvent3, ruleEvent4 ) );
 
         List<RuleEffect> ruleEffects = ruleEngineBuilder.build().evaluate( ruleEvent ).call();
 
@@ -308,7 +308,7 @@ RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
             RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                         RuleDataValue.create(new Date(), "test_program_stage", "test_data_element_two", "condition")), "", null);
 
-        ruleEngineBuilder.events( Arrays.asList( ruleEvent2, ruleEvent3, ruleEvent4 ) );
+        ruleEngineBuilder.events( List.of( ruleEvent2, ruleEvent3, ruleEvent4 ) );
 
         List<RuleEffect> ruleEffects = ruleEngineBuilder.build().evaluate( ruleEvent ).call();
 
@@ -342,7 +342,7 @@ RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
             RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                         RuleDataValue.create(new Date(), "test_program_stage", "test_data_element_one", "-3")), "", null);
 
-        List<RuleEffect> ruleEffects = ruleEngineBuilder.events( Arrays.asList( ruleEvent1, ruleEvent2 ) ).build()
+        List<RuleEffect> ruleEffects = ruleEngineBuilder.events( List.of( ruleEvent1, ruleEvent2 ) ).build()
             .evaluate( ruleEvent ).call();
 
         assertEquals( 1 , ruleEffects.size() );
@@ -375,7 +375,7 @@ RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
             RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                         RuleDataValue.create(new Date(), "test_program_stage", "test_data_element_one", "-3")), "", null);
 
-        List<RuleEffect> ruleEffects = ruleEngineBuilder.events( Arrays.asList( ruleEvent1, ruleEvent2 ) ).build()
+        List<RuleEffect> ruleEffects = ruleEngineBuilder.events( List.of( ruleEvent1, ruleEvent2 ) ).build()
             .evaluate( ruleEvent ).call();
 
         assertEquals( 1 , ruleEffects.size() );
@@ -399,24 +399,24 @@ public void evaluateD2MaxValueIfVariableName()
             .create( null, null, "d2:maxValue(#{" + VARIABLE_NAME + "}) == 8.0", List.of(ruleAction), "", "" );
 
         RuleEngine.Builder ruleEngineBuilder = getRuleEngineBuilder( rule,
-            Arrays.asList( ruleVariableOne, ruleVariableTwo ) );
+            List.of( ruleVariableOne, ruleVariableTwo ) );
 
         RuleEvent ruleEvent1 = RuleEvent.create( "test_event1", "test_program_stage1",
-            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_one", "5" ),
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_two", "male" ) ), "", null);
 
         RuleEvent ruleEvent2 = RuleEvent.create( "test_event2", "test_program_stage2",
-            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_one", "7" ),
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_two", "male" ) ), "", null);
 
         RuleEvent ruleEvent3 = RuleEvent.create( "test_event3", "test_program_stage3",
-            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_one", "8" ),
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_two", "male" ) ), "", null);
 
-        List<RuleEffect> ruleEffects = ruleEngineBuilder.events( Arrays.asList( ruleEvent1, ruleEvent2 ) ).build()
+        List<RuleEffect> ruleEffects = ruleEngineBuilder.events( List.of( ruleEvent1, ruleEvent2 ) ).build()
             .evaluate( ruleEvent3 ).call();
 
         assertEquals( 1 , ruleEffects.size() );
@@ -439,24 +439,24 @@ public void evaluateD2MaxValueIfComposedUid()
             .create( null, null, "d2:maxValue(#{" + UID01 + "}) == 8.0", List.of(ruleAction), "", "" );
 
         RuleEngine.Builder ruleEngineBuilder = getRuleEngineBuilder( rule,
-            Arrays.asList( ruleVariableOne, ruleVariableTwo ) );
+            List.of( ruleVariableOne, ruleVariableTwo ) );
 
         RuleEvent ruleEvent1 = RuleEvent.create( "test_event1", "test_program_stage1",
-            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_one", "5" ),
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_two", "male" ) ), "", null);
 
         RuleEvent ruleEvent2 = RuleEvent.create( "test_event2", "test_program_stage2",
-            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_one", "7" ),
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_two", "male" ) ), "", null);
 
         RuleEvent ruleEvent3 = RuleEvent.create( "test_event3", "test_program_stage3",
-            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_one", "8" ),
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_two", "male" ) ), "", null);
 
-        List<RuleEffect> ruleEffects = ruleEngineBuilder.events( Arrays.asList( ruleEvent1, ruleEvent2 ) ).build()
+        List<RuleEffect> ruleEffects = ruleEngineBuilder.events( List.of( ruleEvent1, ruleEvent2 ) ).build()
             .evaluate( ruleEvent3 ).call();
 
         assertEquals( 1 , ruleEffects.size() );
@@ -478,24 +478,24 @@ public void testMinValueIfVariableName()
         Rule rule = Rule.create( null, null, "true", List.of(ruleAction), "", "" );
 
         RuleEngine.Builder ruleEngineBuilder = getRuleEngineBuilder( rule,
-            Arrays.asList( ruleVariableOne, ruleVariableTwo ) );
+            List.of( ruleVariableOne, ruleVariableTwo ) );
 
         RuleEvent ruleEvent1 = RuleEvent.create( "test_event1", "test_program_stage1",
-            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_one", "5" ),
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_two", "male" ) ), "", null);
 
         RuleEvent ruleEvent2 = RuleEvent.create( "test_event2", "test_program_stage2",
-            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_one", "7" ),
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_two", "male" ) ), "", null);
 
         RuleEvent ruleEvent3 = RuleEvent.create( "test_event3", "test_program_stage3",
-            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_one", "8" ),
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_two", "male" ) ), "", null);
 
-        List<RuleEffect> ruleEffects = ruleEngineBuilder.events( Arrays.asList( ruleEvent1, ruleEvent2 ) ).build()
+        List<RuleEffect> ruleEffects = ruleEngineBuilder.events( List.of( ruleEvent1, ruleEvent2 ) ).build()
             .evaluate( ruleEvent3 ).call();
 
         assertEquals( 1 , ruleEffects.size() );
@@ -518,24 +518,24 @@ public void testMinValueIfComposedUid()
         Rule rule = Rule.create( null, null, "true", List.of(ruleAction), "", "" );
 
         RuleEngine.Builder ruleEngineBuilder = getRuleEngineBuilder( rule,
-            Arrays.asList( ruleVariableOne, ruleVariableTwo ) );
+            List.of( ruleVariableOne, ruleVariableTwo ) );
 
         RuleEvent ruleEvent1 = RuleEvent.create( "test_event1", "test_program_stage1",
-            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_one", "5" ),
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_two", "male" ) ), "", null);
 
         RuleEvent ruleEvent2 = RuleEvent.create( "test_event2", "test_program_stage2",
-            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_one", "7" ),
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_two", "male" ) ), "", null);
 
         RuleEvent ruleEvent3 = RuleEvent.create( "test_event3", "test_program_stage3",
-            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_one", "8" ),
                 RuleDataValue.create( new Date(), "test_program_stage", "test_data_element_two", "male" ) ), "", null);
 
-        List<RuleEffect> ruleEffects = ruleEngineBuilder.events( Arrays.asList( ruleEvent1, ruleEvent2 ) ).build()
+        List<RuleEffect> ruleEffects = ruleEngineBuilder.events( List.of( ruleEvent1, ruleEvent2 ) ).build()
             .evaluate( ruleEvent3 ).call();
 
         assertEquals( 1 , ruleEffects.size() );
diff --git a/src/test/java/org/hisp/dhis/rules/RuleVariableValueMapBuilderTest.java b/src/test/java/org/hisp/dhis/rules/RuleVariableValueMapBuilderTest.java
index 7f4f2fd4..9f8fcf2d 100644
--- a/src/test/java/org/hisp/dhis/rules/RuleVariableValueMapBuilderTest.java
+++ b/src/test/java/org/hisp/dhis/rules/RuleVariableValueMapBuilderTest.java
@@ -23,7 +23,6 @@
 import java.time.LocalDate;
 import java.time.ZoneOffset;
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.Date;
 import java.util.List;
 import java.util.Locale;
@@ -73,11 +72,11 @@ public void currentEventVariableShouldContainNullValueForEnrollmentEvaluation()
         // values from context events should be ignored
         RuleEnrollment ruleEnrollment = RuleEnrollment.create( "test_enrollment",
                 dateFormat.parse( "2015-01-01" ), dateFormat.parse( "2015-01-01" ),
-                RuleEnrollment.Status.ACTIVE, "", null, Arrays.asList(
+                RuleEnrollment.Status.ACTIVE, "", null, List.of(
                         RuleAttributeValue.create( "test_attribute_one", "test_attribute_value_one" ),
                         RuleAttributeValue.create( "test_attribute_two", "test_attribute_value_two" ) ), "" );
         RuleEvent contextEventOne = RuleEvent.create( "test_context_event_one", "test_program_stage",
-                RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
+                RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                         RuleDataValue.create( eventDate, "test_program_stage",
                                 "test_dataelement_one", "test_context_value_one" ),
                         RuleDataValue.create( eventDate, "test_program_stage",
@@ -107,28 +106,28 @@ public void currentEventVariableShouldContainValuesFromCurrentEvent()
 
         // values from context events should be ignored
         RuleEvent contextEventOne = RuleEvent.create( "test_context_event_one", "test_program_stage",
-            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                 RuleDataValue.create( eventDate, "test_program_stage",
                     "test_dataelement_one", "test_context_value_one" ),
                 RuleDataValue.create( eventDate, "test_program_stage",
                     "test_dataelement_two", "test_context_value_two" ) ), "", null);
         RuleEvent contextEventTwo = RuleEvent.create( "test_context_event_two", "test_program_stage",
-            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, List.of(
                 RuleDataValue.create( eventDate, "test_program_stage",
                     "test_dataelement_one", "test_context_value_three" ),
                 RuleDataValue.create( eventDate, "test_program_stage",
                     "test_dataelement_two", "test_context_value_four" ) ), "", null);
         // values from current ruleEvent should be propagated to the variable values
         RuleEvent currentEvent = RuleEvent.create( "test_event_uid", "test_program_stage",
-            RuleEvent.Status.ACTIVE, eventDate, dueDate, "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, eventDate, dueDate, "", null, List.of(
                 RuleDataValue.create( eventDate, "test_program_stage",
                     "test_dataelement_one", "test_value_one" ),
                 RuleDataValue.create( eventDate, "test_program_stage",
                     "test_dataelement_two", "test_value_two" ) ), "", null);
 
         Map<String, RuleVariableValue> valueMap = RuleVariableValueMapBuilder.target( currentEvent )
-            .ruleVariables( Arrays.asList( ruleVariableOne, ruleVariableTwo ) )
-            .ruleEvents( Arrays.asList( contextEventOne, contextEventTwo ) )
+            .ruleVariables( List.of( ruleVariableOne, ruleVariableTwo ) )
+            .ruleEvents( List.of( contextEventOne, contextEventTwo ) )
             .triggerEnvironment( TriggerEnvironment.SERVER )
             .build();
 
@@ -175,27 +174,27 @@ public void newestEventProgramVariableShouldContainValueFromNewestContextEvent()
         Date currentEventDueDate = null;
 
         RuleEvent oldestRuleEvent = RuleEvent.create( "test_event_uid_oldest", "test_program_stage",
-            RuleEvent.Status.ACTIVE, oldestEventDate, oldestEventDate, "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, oldestEventDate, oldestEventDate, "", null, List.of(
                 RuleDataValue.create( oldestEventDate, "test_program_stage",
                     "test_dataelement_one", "test_value_one_oldest" ),
                 RuleDataValue.create( oldestEventDate, "test_program_stage",
                     "test_dataelement_two", "test_value_two_oldest" ) ), "", null);
         RuleEvent newestRuleEvent = RuleEvent.create( "test_event_uid_newest", "test_program_stage",
-            RuleEvent.Status.ACTIVE, newestEventDate, newestEventDate, "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, newestEventDate, newestEventDate, "", null, List.of(
                 RuleDataValue.create( newestEventDate, "test_program_stage",
                     "test_dataelement_one", "test_value_one_newest" ),
                 RuleDataValue.create( newestEventDate, "test_program_stage",
                     "test_dataelement_two", "test_value_two_newest" ) ), "", null);
         RuleEvent currentEvent = RuleEvent.create( "test_event_uid_current", "test_program_stage",
-            RuleEvent.Status.ACTIVE, currentEventDate, currentEventDueDate, "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, currentEventDate, currentEventDueDate, "", null, List.of(
                 RuleDataValue.create( currentEventDate, "test_program_stage",
                     "test_dataelement_one", "test_value_one_current" ),
                 RuleDataValue.create( currentEventDate, "test_program_stage",
                     "test_dataelement_two", "test_value_two_current" ) ), "", null);
 
         Map<String, RuleVariableValue> valueMap = RuleVariableValueMapBuilder.target( currentEvent )
-            .ruleVariables( Arrays.asList( ruleVariableOne, ruleVariableTwo ) )
-            .ruleEvents( Arrays.asList( oldestRuleEvent, newestRuleEvent ) )
+            .ruleVariables( List.of( ruleVariableOne, ruleVariableTwo ) )
+            .ruleEvents( List.of( oldestRuleEvent, newestRuleEvent ) )
             .triggerEnvironment( TriggerEnvironment.SERVER )
             .build();
 
@@ -239,28 +238,28 @@ public void newestEventProgramVariableShouldReturnValuesFromCurrentEventWhenIfNe
         Date dateEventDueCurrent = dateFormat.parse( "2016-01-01" );
 
         RuleEvent firstRuleEvent = RuleEvent.create( "test_event_uid_one", "test_program_stage",
-            RuleEvent.Status.ACTIVE, dateEventOne, dateEventOne, "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, dateEventOne, dateEventOne, "", null, List.of(
                 RuleDataValue.create( dateEventOne, "test_program_stage",
                     "test_dataelement_one", "test_value_dataelement_one_first" ),
                 RuleDataValue.create( dateEventOne, "test_program_stage",
                     "test_dataelement_two", "test_value_dataelement_two_first" ) ), "", null);
         RuleEvent secondRuleEvent = RuleEvent.create( "test_event_uid_two", "test_program_stage",
-            RuleEvent.Status.ACTIVE, dateEventTwo, dateEventTwo, "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, dateEventTwo, dateEventTwo, "", null, List.of(
                 RuleDataValue.create( dateEventTwo, "test_program_stage",
                     "test_dataelement_one", "test_value_dataelement_one_second" ),
                 RuleDataValue.create( dateEventTwo, "test_program_stage",
                     "test_dataelement_two", "test_value_dataelement_two_second" ) ), "", null);
         RuleEvent currentEvent = RuleEvent.create( "test_event_uid_current", "test_program_stage",
-            RuleEvent.Status.ACTIVE, dateEventCurrent, dateEventDueCurrent, "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, dateEventCurrent, dateEventDueCurrent, "", null, List.of(
                 RuleDataValue.create( dateEventCurrent, "test_program_stage",
                     "test_dataelement_one", "test_value_dataelement_one_current" ),
                 RuleDataValue.create( dateEventCurrent, "test_program_stage",
                     "test_dataelement_two", "test_value_dataelement_two_current" ) ), "", null);
 
         Map<String, RuleVariableValue> valueMap = RuleVariableValueMapBuilder.target( currentEvent )
-            .ruleVariables( Arrays.asList( ruleVariableOne, ruleVariableTwo ) )
+            .ruleVariables( List.of( ruleVariableOne, ruleVariableTwo ) )
             .triggerEnvironment( TriggerEnvironment.SERVER )
-            .ruleEvents( Arrays.asList( firstRuleEvent, secondRuleEvent ) )
+            .ruleEvents( List.of( firstRuleEvent, secondRuleEvent ) )
             .build();
 
         assertEquals( 13 , valueMap.size() );
@@ -325,7 +324,7 @@ public void newestEventProgramStageVariableShouldContainValueFromNewestContextEv
 
         Map<String, RuleVariableValue> valueMap = RuleVariableValueMapBuilder.target( eventCurrent )
             .ruleVariables(List.of(ruleVariable))
-            .ruleEvents( Arrays.asList( eventOne, eventTwo, eventThree ) )
+            .ruleEvents( List.of( eventOne, eventTwo, eventThree ) )
             .triggerEnvironment( TriggerEnvironment.SERVER )
             .build();
 
@@ -430,7 +429,7 @@ public void previousEventVariableShouldContainValuesFromPreviousEvent()
         Map<String, RuleVariableValue> valueMap = RuleVariableValueMapBuilder.target( ruleEventCurrent )
             .ruleVariables(List.of(ruleVariable))
             .triggerEnvironment( TriggerEnvironment.SERVER )
-            .ruleEvents( Arrays.asList( ruleEventOne, ruleEventTwo, ruleEventThree ) )
+            .ruleEvents( List.of( ruleEventOne, ruleEventTwo, ruleEventThree ) )
             .build();
 
         assertEquals( 12 , valueMap.size() );
@@ -471,19 +470,19 @@ public void attributeVariableShouldContainValuesFromContextEnrollment()
 
         // values from enrollment should end up in ruleVariables
         RuleEnrollment ruleEnrollment = RuleEnrollment.create( "test_enrollment",
-            enrollmentDate, enrollmentDate, RuleEnrollment.Status.ACTIVE, "", null, Arrays.asList(
+            enrollmentDate, enrollmentDate, RuleEnrollment.Status.ACTIVE, "", null, List.of(
                 RuleAttributeValue.create( "test_attribute_one", "test_attribute_value_one" ),
                 RuleAttributeValue.create( "test_attribute_two", "test_attribute_value_two" ) ), "" );
 
         // values from context events should be ignored
         RuleEvent contextEvent = RuleEvent.create( "test_context_event_one", "test_program_stage",
-            RuleEvent.Status.ACTIVE, eventDate, new Date(), "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, eventDate, new Date(), "", null, List.of(
                 RuleDataValue.create( eventDate, "test_program_stage",
                     "test_dataelement_one", "test_context_value_one" ),
                 RuleDataValue.create( eventDate, "test_program_stage",
                     "test_dataelement_two", "test_context_value_two" ) ), "", null);
         RuleEvent currentEvent = RuleEvent.create( "test_event_uid", "test_program_stage",
-            RuleEvent.Status.ACTIVE, eventDate, eventDate, "", null, Arrays.asList(
+            RuleEvent.Status.ACTIVE, eventDate, eventDate, "", null, List.of(
                 RuleDataValue.create( eventDate, "test_program_stage",
                     "test_dataelement_one", "test_value_one" ),
                 RuleDataValue.create( eventDate, "test_program_stage",
@@ -493,7 +492,7 @@ RuleEvent.Status.ACTIVE, eventDate, new Date(), "", null, Arrays.asList(
         Map<String, RuleVariableValue> valueMap = RuleVariableValueMapBuilder.target( currentEvent )
             .ruleEnrollment( ruleEnrollment )
             .triggerEnvironment( TriggerEnvironment.SERVER )
-            .ruleVariables( Arrays.asList( ruleVariableOne, ruleVariableTwo ) )
+            .ruleVariables( List.of( ruleVariableOne, ruleVariableTwo ) )
             .ruleEvents(List.of(contextEvent))
             .build();
 
@@ -556,7 +555,7 @@ public void ruleEnrollmentValuesShouldBePropagatedToMapCorrectly()
         Date enrollmentDate = dateFormat.parse( "2017-02-02" );
         Date incidentDate = dateFormat.parse( "2017-04-02" );
         RuleEnrollment ruleEnrollment = RuleEnrollment.create( "test_enrollment", incidentDate,
-            enrollmentDate, RuleEnrollment.Status.ACTIVE, "", null, Arrays.asList(
+            enrollmentDate, RuleEnrollment.Status.ACTIVE, "", null, List.of(
                 RuleAttributeValue.create( "test_attribute_one", "test_attribute_value_one" ),
                 RuleAttributeValue.create( "test_attribute_two", "test_attribute_value_two" ),
                 RuleAttributeValue.create( "test_attribute_three", "test_attribute_value_three" ) ), "" );
@@ -567,8 +566,8 @@ public void ruleEnrollmentValuesShouldBePropagatedToMapCorrectly()
             RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null, new ArrayList<RuleDataValue>(), "", null);
 
         Map<String, RuleVariableValue> valueMap = RuleVariableValueMapBuilder.target( ruleEnrollment )
-            .ruleVariables( Arrays.asList( ruleVariableOne, ruleVariableTwo, ruleVariableThree ) )
-            .ruleEvents( Arrays.asList( ruleEventOne, ruleEventTwo ) )
+            .ruleVariables( List.of( ruleVariableOne, ruleVariableTwo, ruleVariableThree ) )
+            .ruleEvents( List.of( ruleEventOne, ruleEventTwo ) )
             .triggerEnvironment( TriggerEnvironment.SERVER )
             .build();
 
@@ -619,7 +618,7 @@ public void MultipleMapBuilderShoulCreateCorrectMapForEnrollmentAndEvents()
         Date enrollmentDate = dateFormat.parse( "2017-02-02" );
         Date incidentDate = dateFormat.parse( "2017-04-02" );
         RuleEnrollment ruleEnrollment = RuleEnrollment.create( "test_enrollment", incidentDate,
-            enrollmentDate, RuleEnrollment.Status.ACTIVE, "", null, Arrays.asList(
+            enrollmentDate, RuleEnrollment.Status.ACTIVE, "", null, List.of(
                 RuleAttributeValue.create( "test_attribute_one", "test_attribute_value_one" ),
                 RuleAttributeValue.create( "test_attribute_two", "test_attribute_value_two" ),
                 RuleAttributeValue.create( "test_attribute_three", "test_attribute_value_three" ) ), "" );
@@ -638,8 +637,8 @@ public void MultipleMapBuilderShoulCreateCorrectMapForEnrollmentAndEvents()
             null );
 
         RuleVariableValueMap ruleVariableValueMap = RuleVariableValueMapBuilder.target( ruleEnrollment )
-            .ruleVariables( Arrays.asList( ruleVariableOne, ruleVariableTwo, ruleVariableThree ) )
-            .ruleEvents( Arrays.asList( ruleEventOne, ruleEventTwo ) )
+            .ruleVariables( List.of( ruleVariableOne, ruleVariableTwo, ruleVariableThree ) )
+            .ruleEvents( List.of( ruleEventOne, ruleEventTwo ) )
             .triggerEnvironment( TriggerEnvironment.SERVER )
             .multipleBuild();
 
diff --git a/src/test/java/org/hisp/dhis/rules/RuleVariableValueTest.java b/src/test/java/org/hisp/dhis/rules/RuleVariableValueTest.java
index 32a11faa..8e203a21 100644
--- a/src/test/java/org/hisp/dhis/rules/RuleVariableValueTest.java
+++ b/src/test/java/org/hisp/dhis/rules/RuleVariableValueTest.java
@@ -6,8 +6,8 @@
 import org.junit.runners.JUnit4;
 
 import java.text.SimpleDateFormat;
-import java.util.Arrays;
 import java.util.Date;
+import java.util.List;
 import java.util.Locale;
 
 import static org.junit.Assert.assertEquals;
@@ -23,7 +23,7 @@ public class RuleVariableValueTest
     public void textValuesMostBeWrapped()
     {
         RuleVariableValue variableValue = RuleVariableValue.create(
-            "test_value", RuleValueType.TEXT, Arrays.asList(
+            "test_value", RuleValueType.TEXT, List.of(
                 "test_value_candidate_one", "test_value_candidate_two" ), dateFormat.format( new Date() ) );
 
         assertEquals( "test_value" , variableValue.value() );
@@ -37,7 +37,7 @@ public void textValuesMostBeWrapped()
     public void wrappedTextValuesMustNotBeDoubleWrapped()
     {
         RuleVariableValue variableValue = RuleVariableValue.create(
-            "test_value", RuleValueType.TEXT, Arrays.asList(
+            "test_value", RuleValueType.TEXT, List.of(
                 "test_value_candidate_one", "test_value_candidate_two" ), dateFormat.format( new Date() ) );
 
         assertEquals( "test_value" , variableValue.value() );
@@ -51,7 +51,7 @@ public void wrappedTextValuesMustNotBeDoubleWrapped()
     public void numericValuesMostNotBeWrapped()
     {
         RuleVariableValue variableValue = RuleVariableValue.create(
-            "1", RuleValueType.NUMERIC, Arrays.asList( "2", "3" ), dateFormat.format( new Date() ) );
+            "1", RuleValueType.NUMERIC, List.of( "2", "3" ), dateFormat.format( new Date() ) );
 
         assertEquals( "1" , variableValue.value() );
         assertEquals( RuleValueType.NUMERIC , variableValue.type() );
@@ -64,7 +64,7 @@ public void numericValuesMostNotBeWrapped()
     public void booleanValuesMostNotBeWrapped()
     {
         RuleVariableValue variableValue = RuleVariableValue.create(
-            "true", RuleValueType.BOOLEAN, Arrays.asList( "false", "false" ), dateFormat.format( new Date() ) );
+            "true", RuleValueType.BOOLEAN, List.of( "false", "false" ), dateFormat.format( new Date() ) );
 
         assertEquals( "true" , variableValue.value() );
         assertEquals( RuleValueType.BOOLEAN , variableValue.type() );
diff --git a/src/test/java/org/hisp/dhis/rules/VariableValueTypeTest.java b/src/test/java/org/hisp/dhis/rules/VariableValueTypeTest.java
index f8df9d90..5ea9575e 100644
--- a/src/test/java/org/hisp/dhis/rules/VariableValueTypeTest.java
+++ b/src/test/java/org/hisp/dhis/rules/VariableValueTypeTest.java
@@ -38,13 +38,11 @@
 import org.hisp.dhis.rules.models.RuleVariable;
 import org.hisp.dhis.rules.models.RuleVariableCurrentEvent;
 import org.hisp.dhis.rules.models.TriggerEnvironment;
-import org.junit.Assert;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
 
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.Collections;
 import java.util.Date;
 import java.util.HashMap;
@@ -67,11 +65,11 @@ public void testNumericVariablesAreComparedCorrectly()
         RuleVariable ruleVariable2 = RuleVariableCurrentEvent
                 .create( "test_variable2", "test_data_element2", RuleValueType.NUMERIC, true, new ArrayList<>());
 
-        RuleEngine ruleEngine = getRuleEngine( rule, Arrays.asList( ruleVariable, ruleVariable2 ) );
+        RuleEngine ruleEngine = getRuleEngine( rule, List.of( ruleVariable, ruleVariable2 ) );
 
         RuleEvent ruleEvent = RuleEvent.create( "test_event", "test_program_stage",
                 RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null,
-                Arrays.asList(RuleDataValue.create(new Date(), "", "test_data_element", "30"),
+                List.of(RuleDataValue.create(new Date(), "", "test_data_element", "30"),
                         RuleDataValue.create(new Date(), "", "test_data_element2", "4")), "", null);
         List<RuleEffect> ruleEffects = ruleEngine.evaluate( ruleEvent ).call();
 
@@ -92,11 +90,11 @@ public void testTextVariablesAreComparedCorrectly()
         RuleVariable ruleVariable2 = RuleVariableCurrentEvent
                 .create( "test_variable2", "test_data_element2", RuleValueType.TEXT, true, new ArrayList<>());
 
-        RuleEngine ruleEngine = getRuleEngine( rule, Arrays.asList( ruleVariable, ruleVariable2 ) );
+        RuleEngine ruleEngine = getRuleEngine( rule, List.of( ruleVariable, ruleVariable2 ) );
 
         RuleEvent ruleEvent = RuleEvent.create( "test_event", "test_program_stage",
                 RuleEvent.Status.ACTIVE, new Date(), new Date(), "", null,
-                Arrays.asList(RuleDataValue.create(new Date(), "", "test_data_element", "30"),
+                List.of(RuleDataValue.create(new Date(), "", "test_data_element", "30"),
                         RuleDataValue.create(new Date(), "", "test_data_element2", "4")), "", null);
         List<RuleEffect> ruleEffects = ruleEngine.evaluate( ruleEvent ).call();
 
diff --git a/src/test/java/org/hisp/dhis/rules/models/CalculatedValueTest.java b/src/test/java/org/hisp/dhis/rules/models/CalculatedValueTest.java
index 9c8f3a1c..7490c330 100644
--- a/src/test/java/org/hisp/dhis/rules/models/CalculatedValueTest.java
+++ b/src/test/java/org/hisp/dhis/rules/models/CalculatedValueTest.java
@@ -76,7 +76,7 @@ public void evaluateTenThousandRulesTest()
             .dueDate( new Date() )
             .organisationUnit( "" )
             .organisationUnitCode( "" )
-            .dataValues( Arrays.asList( RuleDataValue.create(
+            .dataValues( List.of( RuleDataValue.create(
                 new Date(), "test_program_stage", "test_data_element", "test_value" ) ) )
             .build();
 
@@ -92,11 +92,11 @@ public void sendMessageMustGetValueFromAssignAction()
     {
         RuleAction assignAction = RuleActionAssign.create( "#{test_calculated_value}", "2+2", null );
         org.hisp.dhis.rules.models.Rule rule = org.hisp.dhis.rules.models.Rule
-            .create( null, 1, "true", Arrays.asList( assignAction ), "test_program_rule1", "" );
+            .create( null, 1, "true", List.of( assignAction ), "test_program_rule1", "" );
 
         RuleAction sendMessageAction = RuleActionSendMessage.create( "test_notification", "4" );
         org.hisp.dhis.rules.models.Rule rule2 = org.hisp.dhis.rules.models.Rule
-            .create( null, 4, "#{test_calculated_value}==4", Arrays.asList( sendMessageAction ), "test_program_rule2",
+            .create( null, 4, "#{test_calculated_value}==4", List.of( sendMessageAction ), "test_program_rule2",
                 "" );
 
         RuleEnrollment enrollment = RuleEnrollment.builder()
@@ -119,11 +119,11 @@ public void sendMessageMustGetValueFromAssignAction()
             .dueDate( new Date() )
             .organisationUnit( "" )
             .organisationUnitCode( "" )
-            .dataValues( Arrays.asList( RuleDataValue.create(
+            .dataValues( List.of( RuleDataValue.create(
                 new Date(), "test_program_stage", "test_data_element", "test_value" ) ) )
             .build();
 
-        RuleEngine ruleEngine = getRuleEngine( Arrays.asList( rule, rule2 ) ).enrollment( enrollment ).build();
+        RuleEngine ruleEngine = getRuleEngine( List.of( rule, rule2 ) ).enrollment( enrollment ).build();
         List<RuleEffect> ruleEffects = ruleEngine.evaluate( ruleEvent ).call();
 
         assertEquals( "4" , ruleEffects.get( 0 ).data() );
@@ -135,11 +135,11 @@ private List<org.hisp.dhis.rules.models.Rule> createRules( int i )
         List<org.hisp.dhis.rules.models.Rule> rules = new ArrayList<>();
         RuleAction assignAction = RuleActionAssign.create( "#{test_calculated_value}", "2+2", null );
         org.hisp.dhis.rules.models.Rule rule = org.hisp.dhis.rules.models.Rule
-            .create( null, 1, "true", Arrays.asList( assignAction ), "test_program_rule1", "" );
+            .create( null, 1, "true", List.of( assignAction ), "test_program_rule1", "" );
 
         RuleAction sendMessageAction = RuleActionSendMessage.create( "test_notification", "4" );
         org.hisp.dhis.rules.models.Rule rule2 = org.hisp.dhis.rules.models.Rule
-            .create( null, 4, "#{test_calculated_value}==4", Arrays.asList( sendMessageAction ), "test_program_rule2",
+            .create( null, 4, "#{test_calculated_value}==4", List.of( sendMessageAction ), "test_program_rule2",
                 "" );
         for ( int j = 0; j < i; j++ )
         {
@@ -155,14 +155,14 @@ public void sendMessageMustGetValueFromAssignActionInSingleExecution()
     {
         RuleAction assignAction = RuleActionAssign.create( "#{test_calculated_value}", "2+2", null );
         org.hisp.dhis.rules.models.Rule rule = org.hisp.dhis.rules.models.Rule
-            .create( null, 1, "true", Arrays.asList( assignAction ), "test_program_rule1", "" );
+            .create( null, 1, "true", List.of( assignAction ), "test_program_rule1", "" );
 
         RuleAction sendMessageAction = RuleActionSendMessage.create( "test_notification", "4.0" );
         org.hisp.dhis.rules.models.Rule rule2 = org.hisp.dhis.rules.models.Rule
-            .create( null, 4, "#{test_calculated_value}==4.0", Arrays.asList( sendMessageAction ),
+            .create( null, 4, "#{test_calculated_value}==4.0", List.of( sendMessageAction ),
                 "test_program_rule2", "" );
 
-        RuleEngine.Builder ruleEngineBuilder = getRuleEngine( Arrays.asList( rule, rule2 ) );
+        RuleEngine.Builder ruleEngineBuilder = getRuleEngine( List.of( rule, rule2 ) );
 
         RuleEnrollment enrollment = RuleEnrollment.builder()
             .enrollment( "test_enrollment" )
@@ -184,7 +184,7 @@ public void sendMessageMustGetValueFromAssignActionInSingleExecution()
             .dueDate( new Date() )
             .organisationUnit( "" )
             .organisationUnitCode( "" )
-            .dataValues( Arrays.asList( RuleDataValue.create(
+            .dataValues( List.of( RuleDataValue.create(
                 new Date(), "test_program_stage", "test_data_element", "test_value" ) ) )
             .build();
 
@@ -205,7 +205,7 @@ private RuleEngine.Builder getRuleEngine( List<org.hisp.dhis.rules.models.Rule>
         return RuleEngineContext
             .builder()
             .rules( rules )
-            .ruleVariables( Arrays.asList( ruleVariable ) )
+            .ruleVariables( List.of( ruleVariable ) )
             .supplementaryData( new HashMap<String, List<String>>() )
             .constantsValue( new HashMap<String, String>() )
             .build().toEngineBuilder().triggerEnvironment( TriggerEnvironment.SERVER );
diff --git a/src/test/java/org/hisp/dhis/rules/models/RuleEnrollmentTest.java b/src/test/java/org/hisp/dhis/rules/models/RuleEnrollmentTest.java
index 18e647f8..f738a07d 100644
--- a/src/test/java/org/hisp/dhis/rules/models/RuleEnrollmentTest.java
+++ b/src/test/java/org/hisp/dhis/rules/models/RuleEnrollmentTest.java
@@ -5,7 +5,6 @@
 import org.junit.runners.JUnit4;
 
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.Date;
 import java.util.List;
 
@@ -33,7 +32,7 @@ public void createShouldPropagatePropertiesCorrectly()
 
         RuleEnrollment ruleEnrollment = RuleEnrollment.create( "test_enrollment",
             incidentDate, enrollmentDate, RuleEnrollment.Status.ACTIVE, "", "",
-            Arrays.asList( ruleAttributeValueOne, ruleAttributeValueTwo, ruleAttributeValueThree ), "" );
+            List.of( ruleAttributeValueOne, ruleAttributeValueTwo, ruleAttributeValueThree ), "" );
 
         assertEquals( "test_enrollment" , ruleEnrollment.enrollment() );
         assertEquals( incidentDate , ruleEnrollment.incidentDate() );
diff --git a/src/test/java/org/hisp/dhis/rules/models/RuleEventTest.java b/src/test/java/org/hisp/dhis/rules/models/RuleEventTest.java
index d4e3514b..337a669a 100644
--- a/src/test/java/org/hisp/dhis/rules/models/RuleEventTest.java
+++ b/src/test/java/org/hisp/dhis/rules/models/RuleEventTest.java
@@ -7,7 +7,6 @@
 import java.text.ParseException;
 import java.text.SimpleDateFormat;
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.Date;
 import java.util.List;
 import java.util.Locale;
@@ -76,13 +75,13 @@ public void eventDateComparatorTest()
         throws ParseException
     {
         SimpleDateFormat dateFormat = new SimpleDateFormat( DATE_PATTERN, Locale.US );
-        List<RuleEvent> ruleEvents = Arrays.asList(
+        List<RuleEvent> ruleEvents = new ArrayList<>(List.of(
             RuleEvent.create( "test_event_one", "test_program_stage_one", RuleEvent.Status.ACTIVE,
                 dateFormat.parse( "2014-02-11" ), dateFormat.parse( "2014-02-11" ), "", null,
-                new ArrayList<RuleDataValue>(), "", null),
+                    new ArrayList<>(), "", null),
             RuleEvent.create( "test_event_two", "test_program_stage_two", RuleEvent.Status.ACTIVE,
                 dateFormat.parse( "2017-03-22" ), dateFormat.parse( "2017-03-22" ), "", null,
-                new ArrayList<RuleDataValue>(), "", null) );
+                    new ArrayList<>(), "", null) ));
 
         ruleEvents.sort(RuleEvent.EVENT_DATE_COMPARATOR);