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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 requires_auth(func):
 """Handle authentication checks. .. py:decorator:: requires_auth Checks if the token has expired and performs authentication if needed. """

    @six.wraps(func)
    def wrapper(self, *args, **kwargs):
        if self.token_expired:
            self.authenticate()
        return func(self, *args, **kwargs)
    return wrapper