What is the intended way of sending an object of type bytes in a Python ROS2 node?

The best solution I have right now uses UInt8MultiArray and a combination of list to convert bytes into a list of integers in the sender, and bytes to convert the list of integers back to bytes in the receiver.

Here is an example of code that uses UInt8MultiArray with list/bytes conversion:

import rclpy
from rclpy.node import Node
from std_msgs.msg import UInt8MultiArray

class Test(Node):
    def __init__(self):
        super().__init__('minimal_pubsub')
        self.publisher_ = self.create_publisher(UInt8MultiArray, 'topic', 10)
        self.create_subscription(UInt8MultiArray, 'topic',self.listener_callback, 10)
        self.timer = self.create_timer(1, self.timer_callback)

    def timer_callback(self):
        input_bytes = b'Bytes'
        msg = UInt8MultiArray(data = list(input_bytes))
        self.publisher_.publish(msg)

    def listener_callback(self, msg):
        output_bytes = bytes(msg.data)
        print(output_bytes)

def main(args=None):
    rclpy.init(args=args)
    test= Test()
    rclpy.spin(test)
    test.destroy_node()
    rclpy.shutdown()

if __name__ == '__main__':
    main()

This works, but it does not seem very elegant.

I have not succeeded in creating a working and elegant solution with ByteMultiArray. For example, the following code:

...
        input_bytes = b'Bytes'
        msg = ByteMultiArray(data = input_bytes)
...

gives an error.

AssertionError: The 'data' field must be a set or sequence and each value of type 'bytes'