message: Fix missing import.
  Test Plan: Tests pass
  Reviewers: georgep, davidn, stephenm, romand
  Subscribers: danielet
diff: @@ -20,6 +20,7 @@ Popnn embedding operator
  from functools import reduce
  from operator import mul
  import tensorflow as tf
  +from tensorflow.python.platform import tf_logging as logging
  def embedding_lookup(params,
  