def add_on_return_callback(self, callback):
        self._impl.add_on_return_callback(
            lambda _channel, method, properties, body: (
                self._add_pending_event(
                    _ReturnedMessageEvt(
                        callback, self, method, properties, body))))
tests False mapping not created.
dataset/ETHPy150Open pika/pika/pika/adapters/blocking_connection.py/BlockingChannel.add_on_return_callback--crossover with--dataset/ETHPy150Open saltstack/salt/tests/unit/modules/boto_lambda_test.py/BotoLambdaEventSourceMappingTestCase.test_that_when_creating_an_event_source_mapping_fails_the_create_event_source_mapping_method_returns_error