def removeWriter(self, writer):
        """
        Remove a C{FileDescriptor} from notification of data available to
        write.
        """
        try:
            self._writers.remove(writer)
        except KeyError:
            return
        self._checkLoop()

        Remove a C{FileDescriptor} from notification of data available to
        write.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/internet/posixbase.py