message: Update docs as per
diff: @@ -112,8 +112,8 @@ For example, the following method programmatically determines the rank
  of the `tf.Tensor` defined in the previous section:
  ```python
  -r = tf.rank(my3d)
  -# After the graph runs, r will hold the value 3.
  +r = tf.rank(my_image)
  +# After the graph runs, r will hold the value 4.
  ```
  ### Referring to `tf.Tensor` slices
  