message: unique doctest
diff: @@ -1622,14 +1622,15 @@ def unique(x, out_idx=dtypes.int32, name=None):
  y[idx[i]] = x[i] for i in [0, 1,...,rank(x) - 1]
  - For example:
  + #### EXAMPLE:
  - ```python
  - # tensor 'x' is [1, 1, 2, 4, 4, 4, 7, 8, 8]
  - y, idx = unique(x)
  - y ==> [1, 2, 4, 7, 8]
  - idx ==> [0, 0, 1, 2, 2, 2, 3, 4, 4]
  - ```
  + >>> x = tf.constant([1, 1, 2, 4, 4, 4, 7, 8, 8])
  + >>> y, idx = tf.unique(x)
  + >>> sess=tf.compat.v1.Session()
  + >>> print(sess.run(y))
  + [1, 2, 4, 7, 8]
  + >>> print(sess.run(idx))
  + [0, 0, 1, 2, 2, 2, 3, 4, 4]
  Args:
  x: A Tensor. 1-D.
  