reorg the struct

pkg/writers/buffered_file_writer/bufferedfilewriter.go

@@ -20,11 +20,12 @@ var bufferPool = sync.Pool{
 
 // BufferedFileWriter manages a buffer for writing data, flushing to a file when a threshold is exceeded.
 type BufferedFileWriter struct {
-	threshold uint64         // Threshold for switching to file writing.
-	buf       bytes.Buffer   // Buffer for storing data under the threshold in memory.
-	filename  string         // Name of the temporary file.
-	file      io.WriteCloser // File for storing data over the threshold.
-	size      uint64         // Total size of the data written.
+	threshold uint64 // Threshold for switching to file writing.
+	size      uint64 // Total size of the data written.
+
+	buf      bytes.Buffer   // Buffer for storing data under the threshold in memory.
+	filename string         // Name of the temporary file.
+	file     io.WriteCloser // File for storing data over the threshold.
 }
 
 // Option is a function that modifies a BufferedFileWriter.