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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 driver(self):
 """ Return the driver of this agent related to. None if the driver is not ready to bind. Returns: :py:class:`inherit from Poco <poco.pocofw.Poco>`: the driver of this agent related to. """


        if not self._driver:
            raise AttributeError("`driver` is not bound on this agent implementation({}). "
                                 "Do you forget to call `super().on_bind_driver` when you override the method "
                                 "`on_bind_driver` in your sub class?"
                                 .format(repr(self)))
        return self._driver