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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 authenticate(self, token):
 """ Authenticate a token :param token: """

        if self.verify_token_callback:
            # Specified verify function overrides below
            return self.verify_token_callback(token)

        if not token:
            return False

        name = self.token_manager.verify(token)
        if not name:
            return False

        return True