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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def future_add_done_callback( # noqa: F811 ) -> None: """Arrange to call ``callback`` when ``future`` is complete. ``callback`` is invoked with one argument, the ``future``. If ``future`` is already done, ``callback`` is invoked immediately. This may differ from the behavior of ``Future.add_done_callback``, which makes no such guarantee. .. versionadded:: 5.0 """

    if future.done():
        callback(future)
    else:
        future.add_done_callback(callback)