def __init__(self, filename, registry=None, reactor=None):
        """
        Initialize, with the name of a CGI script file.
        """
        self.filename = filename
        if reactor is None:
            # This installs a default reactor, if None was installed before.
            # We do a late import here, so that importing the current module
            # won't directly trigger installing a default reactor.
            from twisted.internet import reactor
        self._reactor = reactor

        Initialize, with the name of a CGI script file.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/web/twcgi.py