def flush(self):
        """
        Nothing is buffered, so flushing does nothing.  This method is required
        to exist by PEP 333, though.

        This is called in a WSGI application thread, not the I/O thread.
        """

        Nothing is buffered, so flushing does nothing.  This method is required
        to exist by PEP 333, though.

        This is called in a WSGI application thread, not the I/O thread.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/web/wsgi.py