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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 after_serving(self, func: Callable) -> Callable: """Add a after serving function. This will allow the function provided to be called once after anything is served (after last byte is sent). This is designed to be used as a decorator. An example usage, .. code-block:: python @app.after_serving def func():
 Arguments: func: The function itself. """

        handler = ensure_coroutine(func)
        self.after_serving_funcs.append(handler)
        return func