message: According to suggestions...
diff: @@ -4493,15 +4493,28 @@ def where_v2(condition, x=None, y=None, name=None):
  no asymptote, and to avoid computing a value whose gradient is NaN by
  replacing dangerous inputs with safe inputs.
  - Instead of this
  + Here down a couple of examples:
  +
  + 1. Instead of this
  >>> y = float(-1)
  >>> tf.where(y > 0, tf.sqrt(y), y)
  Use this
  + >>> tf.where(y > 0, tf.sqrt(tf.where(y > 0, y, 1)), y)
  + <tf.Tensor: shape=(), dtype=float32, numpy=-1.0>
  +
  + 2. Instead of this
  +
  + >>> y = tf.constant(-1, dtype=tf.float32)
  + >>> tf.where(y > 0, tf.sqrt(y), y)
  +
  + Use this
  +
  >>> tf.where(y > 0, tf.sqrt(tf.where(y > 0, y, 1)), y)
  + <tf.Tensor: shape=(), dtype=float32, numpy=-1.0>
  Args:
  condition: A `tf.Tensor` of type `bool`
  x: If provided, a Tensor which is of the same type as `y`, and has a shape
  