'Remove a file descriptor from the set
:param int fileno: The file descriptor'

def remove_handler(self, fileno):

    try:
        del self._processing_fd_event_map[fileno]
    except KeyError:
        pass
    (events_cleared, _) = self._set_handler_events(fileno, 0)
    del self._fd_handlers[fileno]
    self._unregister_fd(fileno, events_to_clear=events_cleared)
