message: Update the documentation for GraphNetwork to refer to tf.keras.models rather than "model".
diff: @@ -181,11 +181,11 @@ def Input( # pylint: disable=invalid-name
  class GraphNetwork(base.Layer):
  """A GraphNetwork is a directed acyclic graph of layers.
  - It is the topological form of a "model".
  - A Model is simply a GraphNetwork with added training/evaluation routines.
  + It is the topological form of a `tf.keras.models.Model`. A `Model` is simply a
  + `GraphNetwork` with added training/evaluation routines.
  - A GraphNetwork instance implements the full Layer API. In particular, a
  - GraphNetwork can be called on new inputs.
  + A `GraphNetwork` instance implements the full `Layer` API. In particular, a
  + `GraphNetwork` can be called on new inputs.
  Example:
  