def test_yieldsMachineInClass(self):
        """
        When given a L{twisted.python.modules.PythonAttribute} that refers
        to a class that contains a L{MethodicalMachine} as a class
        variable, L{findMachinesViaWrapper} yields that machine and
        its FQPN.
        """
        source = """\
        from automat import MethodicalMachine

        class PythonClass(object):
            _classMachine = MethodicalMachine()
        """
        moduleDict = self.makeModuleAsDict(source, self.pathDir, 'clsmod.py')
        PythonClass = moduleDict['clsmod.PythonClass']
        self.assertIn(('clsmod.PythonClass._classMachine',
                       PythonClass.load()._classMachine),
                      list(self.findMachinesViaWrapper(PythonClass)))

        When given a L{twisted.python.modules.PythonAttribute} that refers
        to a class that contains a L{MethodicalMachine} as a class
        variable, L{findMachinesViaWrapper} yields that machine and
        its FQPN.
        
stackoverflow/venv/lib/python3.6/site-packages/automat/_test/test_discover.py