From 2840d14692698bfc167acf8f0374f5407b9f8733 Mon Sep 17 00:00:00 2001
From: Bala Wang <xiaodan.w@outlook.com>
Date: Tue, 12 Jan 2021 17:43:52 +0800
Subject: [PATCH] Can create tree with items from different levels

---
 src/Collection.php | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/Collection.php b/src/Collection.php
index 2dd26df..118c911 100644
--- a/src/Collection.php
+++ b/src/Collection.php
@@ -64,7 +64,7 @@ public function toTree($root = false)
 
         /** @var Model|NodeTrait $node */
         foreach ($this->items as $node) {
-            if ($node->getParentId() == $root) {
+            if ($node->getParentId() == $root || ! $node->getParentId()) {
                 $items[] = $node;
             }
         }
@@ -140,4 +140,4 @@ protected function flattenTree(self $groupedNodes, $parentId)
         return $this;
     }
 
-}
\ No newline at end of file
+}