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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 update_cache(func):
 """Decorate functions that modify the internally stored usernotes JSON. Ensures that updates are mirrored onto reddit. Arguments: func: the function being decorated """

    @wraps(func)
    def wrapper(self, *args, **kwargs):
        """The wrapper function."""
        lazy = kwargs.get('lazy', False)
        kwargs.pop('lazy', None)

        if not lazy:
            self.get_json()

        ret = func(self, *args, **kwargs)

        # If returning a string assume it is an update message
        if isinstance(ret, str) and not lazy:
            self.set_json(ret)
        else:
            return ret

    return wrapper