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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 unbind_handler(self, svc_ref):
 """ Called if a command service is gone. Unregisters its commands. :param svc_ref: A reference to the unbound service :return: True if the commands have been unregistered """

        if svc_ref not in self._bound_references:
            # Unknown reference
            return False

        # Unregister its commands
        namespace, commands = self._reference_commands[svc_ref]
        for command in commands:
            self.unregister(namespace, command)

        # Release the service
        self._context.unget_service(svc_ref)
        del self._bound_references[svc_ref]
        del self._reference_commands[svc_ref]
        return True