def postOptions(self):
        """
        I am called after the options are parsed.

        Override this method in your subclass to do something after
        the options have been parsed and assigned, like validate that
        all options are sane.
        """

        I am called after the options are parsed.

        Override this method in your subclass to do something after
        the options have been parsed and assigned, like validate that
        all options are sane.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/python/usage.py