'Remove a Selectable for notification of data available to write.'

def removeWriter(self, writer):

    if (writer in self._writers):
        fd = self._writers.pop(writer)
        (reader, _) = self._fds[fd]
        if reader:
            self._fds[fd] = (reader, None)
            self._io_loop.update_handler(fd, IOLoop.READ)
        else:
            del self._fds[fd]
            self._io_loop.remove_handler(fd)
