def available():
        """
        Is the reservation available?

        @return: L{True} if the reserved file descriptor is open and
            can thus be closed to allow a new file to be opened in its
            place; L{False} if it is not open.
        """

        Is the reservation available?

        @return: L{True} if the reserved file descriptor is open and
            can thus be closed to allow a new file to be opened in its
            place; L{False} if it is not open.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/internet/tcp.py