message: Add doc strings for kullback_leibler_divergence
diff: @@ -977,7 +977,31 @@ def binary_crossentropy(y_true, y_pred, from_logits=False, label_smoothing=0):
  'keras.losses.kullback_leibler_divergence',
  'keras.losses.kld',
  'keras.losses.KLD')
  -def kullback_leibler_divergence(y_true, y_pred): # pylint: disable=missing-docstring
  +def kullback_leibler_divergence(y_true, y_pred):
  + """Computes Kullback-Leibler divergence loss between `y_true` and `y_pred`.
  +
  + `loss = y_true * log(y_true / y_pred)`
  +
  + See: https://en.wikipedia.org/wiki/Kullback%E2%80%93Leibler_divergence
  +
  + Usage:
  +
  + ```python
  + loss = tf.keras.losses.KLD([.4, .9, .2], [.5, .8, .12])
  + print('Loss: ', loss.numpy()) # Loss: 0.11891246
  + ```
  +
  + Args:
  + y_true: Tensor of true targets.
  + y_pred: Tensor of predicted targets.
  +
  + Returns:
  + A `Tensor` with loss.
  +
  + Raises:
  + TypeError: If `y_true` cannot be cast to the `y_pred.dtype`.
  +
  + """
  y_pred = ops.convert_to_tensor(y_pred)
  y_true = math_ops.cast(y_true, y_pred.dtype)
  y_true = K.clip(y_true, K.epsilon(), 1)
  