def setUp(self):
        """
        Override the L{reactors.getPlugins} function, normally bound to
        L{twisted.plugin.getPlugins}, in order to control which
        L{IReactorInstaller} plugins are seen as available.

        C{self.pluginResults} can be customized and will be used as the
        result of calls to C{reactors.getPlugins}.
        """
        self.pluginCalls = []
        self.pluginResults = []
        self.originalFunction = reactors.getPlugins
        reactors.getPlugins = self._getPlugins

        Override the L{reactors.getPlugins} function, normally bound to
        L{twisted.plugin.getPlugins}, in order to control which
        L{IReactorInstaller} plugins are seen as available.

        C{self.pluginResults} can be customized and will be used as the
        result of calls to C{reactors.getPlugins}.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_application.py