def METHOD_NAME(api, parent_id):
    # Post some data
    for c in reversed(string.ascii_lowercase):
        api.PostReply(threads_pb2.PostReplyReq(thread_id=parent_id, content=c))
    # Get it with pagination
    token = ""
    import textwrap
    for expected_page in textwrap.wrap(string.ascii_lowercase, 5):
        ret = api.GetThread(threads_pb2.GetThreadReq(thread_id=parent_id, page_size=5, page_token=token))
        assert "".join(x.content for x in ret.replies) == expected_page
        token = ret.next_page_token
    assert token == ""
    return ret.replies[0].thread_id  # to be used as a test one level deeper