def register_write(self, fd, callback):
        """Register `fd` for select.  Will `callback` when writeable."""
        assert fd not in self._wcallbacks
        self._wcallbacks[fd] = callback
        self.control(SelectTask.NEWFD)
        #self.logger.debug('Registered %s for write on %d', callback, fd)
dataset/ETHPy150Open facebook/sparts/sparts/tasks/select.py/SelectTask.register_write/original