async def METHOD_NAME(ep):
    """
    Basic echo server for sized messages.
    We expect the other endpoint to follow the pattern::
    # size of the real message (in bytes)
    >>> await ep.send(msg_size)
    >>> await ep.send(msg)       # send the real message
    >>> await ep.recv(responds)  # receive the echo
    """
    msg_size = np.empty(1, dtype=np.uint64)
    await ep.recv(msg_size)
    msg = create_empty_data(msg_size[0])
    await ep.recv(msg)
    await ep.send(msg)
    await ep.close()