## Bug report **Required Info:** - Operating System: - focal - Installation type: - source - Version or commit hash: - master - DDS implementation: - n/a - Client library (if applicable): - rclpy #### Steps to reproduce issue ```python3 from test_msgs.msg import UnboundedSequences msg = UnboundedSequences() msg.byte_values = b'ffff' ``` #### Expected behavior A `bytes` instance should be accepted, as it is the type documented in the design doc. http://design.ros2.org/articles/idl_interface_definition.html #### Actual behavior ```python3 >>> from test_msgs.msg import UnboundedSequences >>> msg = UnboundedSequences() >>> msg.byte_values = msg.byte_values = b'ffff' Traceback (most recent call last): File "<stdin>", line 1, in <module> File "/home/sloretz/ws/ros2/install/test_msgs/lib/python3.8/site-packages/test_msgs/msg/_unbounded_sequences.py", line 466, in byte_values assert \ AssertionError: The 'byte_values' field must be a set or sequence and each value of type 'bytes' ``` It only accepts a sequence of bytes instances ```python3 msg.byte_values = (b'ff', b'ff') ``` #### Additional information I noticed while reviewing #129