def removeObserver(self, observer):
        """
        Unregisters an observer with this publisher.

        @param observer: An L{ILogObserver} to remove.
        """
        try:
            self._observers.remove(observer)
        except ValueError:
            pass

        Unregisters an observer with this publisher.

        @param observer: An L{ILogObserver} to remove.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/logger/_observer.py