def test_containsMachineFeatures(self):
        """
        The output of L{graphviz} should contain the names of the states,
        inputs, outputs in the state machine.
        """
        gvout = "".join(sampleMachine().asDigraph())
        self.assertIn("begin", gvout)
        self.assertIn("end", gvout)
        self.assertIn("go", gvout)
        self.assertIn("out", gvout)

        The output of L{graphviz} should contain the names of the states,
        inputs, outputs in the state machine.
        
stackoverflow/venv/lib/python3.6/site-packages/automat/_test/test_visualize.py