diff --git a/protocol/src/main/resources/php/ByteBuffer.php b/protocol/src/main/resources/php/ByteBuffer.php
index 6067ab17..5481c09b 100644
--- a/protocol/src/main/resources/php/ByteBuffer.php
+++ b/protocol/src/main/resources/php/ByteBuffer.php
@@ -32,6 +32,7 @@ class ByteBuffer
             $this->writeInt($length);
             $this->writeOffset = $currentwriteIndex;
         } else {
+            // substr is deep clone
             $bytes = substr($this->buffer, $currentwriteIndex - $length, $length);
             $this->writeOffset = $beforewriteIndex;
             $this->writeInt($length);
diff --git a/protocol/src/main/resources/python/ByteBuffer.py b/protocol/src/main/resources/python/ByteBuffer.py
index 3f10b45b..5ebe7623 100644
--- a/protocol/src/main/resources/python/ByteBuffer.py
+++ b/protocol/src/main/resources/python/ByteBuffer.py
@@ -25,6 +25,7 @@ class ByteBuffer():
             self.writeInt(length)
             self.setWriteOffset(currentWriteIndex)
         else:
+            # slice of bytearray is deep clone
             retainedByteBuf = self.buffer[(currentWriteIndex - length):currentWriteIndex]
             self.setWriteOffset(beforeWriteIndex)
             self.writeInt(length)