message: Update lookup_ops.py
diff: @@ -64,6 +64,7 @@ def initialize_all_tables(name="init_all_tables"):
  @tf_export(v1=["initializers.tables_initializer", "tables_initializer"])
  def tables_initializer(name="init_all_tables"):
  """Returns an Op that initializes all tables of the default graph.
  +
  See the [Low Level Intro](https://www.tensorflow.org/guide/low_level_intro#feature_columns)
  guide, for an example of usage.
  