def init_callback(d: ApiDefinition, m: Callable, cb: str):
    if ((d.callback_methods is not None) or (d.done_method is not None)):
        return f'{current_request_state(d, m)}.{cb} = {cb}'
    return ''
def init_callback(d: ApiDefinition, m: Callable, cb: str):
    if ((d.callback_methods is not None) or (d.done_method is not None)):
        return f'{current_request_state(d, m)}.{cb} = {cb}'
    return 