def test_reactorInstallation(self):
        """
        Test that L{reactors.Reactor.install} loads the correct module and
        calls its install attribute.
        """
        installed = []
        def install():
            installed.append(True)
        fakeReactor = FakeReactor(install,
                                  'fakereactortest', __name__, 'described')
        modules = {'fakereactortest': fakeReactor}
        self.replaceSysModules(modules)
        installer = reactors.Reactor('fakereactor', 'fakereactortest', 'described')
        installer.install()
        self.assertEqual(installed, [True])

        Test that L{reactors.Reactor.install} loads the correct module and
        calls its install attribute.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_application.py