import tensorflow as tf

          'bar': tf.convert_to_tensor([0, 2, 0, 2], dtype=tf.int64),
      }

      # Annotate an arbitrary proto at the schema level (not sure what global
      # schema boundaries would mean, but hey I'm just a test).
      boundaries = tf.constant([[1.0]])
      message_type = annotations_pb2.BucketBoundaries.DESCRIPTOR.full_name
      sizes = tf.expand_dims([tf.size(boundaries)], axis=0)
      message_proto = tf.raw_ops.EncodeProto(
          sizes=sizes, values=[tf.cast(boundaries, tf.float32)],
