def test__message_received(self, mockmr): procmock = Mock() procmock.push_context = MagicMock() ep = ProcessRPCResponseEndpointUnit(process=procmock) ep._message_received(sentinel.msg, sentinel.headers) procmock.push_context.assert_called_once_with(sentinel.headers) procmock.push_context().__enter__.assert_called_once_with() mockmr.assert_called_once_with(ep, sentinel.msg, sentinel.headers)