import tensorflow as tf

    self.unweighted_xent = _SafeXEnt(self.y, self.probs)

    self._xent = _SafeXEnt(self.y, self.probs, class_weights=weights)

    self.cost = tf.reduce_mean(self.example_weights * self._xent)


class TweetSeqModel(BaseModel): #formerly SeqModel
