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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 destroy(self):
 """Remove a unit from the fleet cluster Returns: True: The unit was removed Raises: fleet.v1.errors.APIError: Fleet returned a response code >= 400 """


        # if this unit didn't come from fleet, we can't destroy it
        if not self._is_live():
            raise RuntimeError('A unit must be submitted to fleet before it can destroyed.')

        return self._client.destroy_unit(self.name)