# See https://cloud.google.com/architecture/using-container-images#exploring_image_manifests_digests_and_tags
          echo -n "Trying to map name $1 to tag $2... "
          digest=$(curl -s --head "https://gcr.io/v2/tensorflow-sigs/build/manifests/$2" | egrep -o "sha256:[[:alnum:]]*")
          # Find the line matching the regex "sigbuild-r2.9" (with quotes) and
          # replace just the digest portion in it

        should switch to
        `tf.estimator.Estimator.experimental_export_all_saved_models`.
    *   Update `regression_head` to the new Head API for Canned Estimator V2.
    *   Switch `multi_class_head` to Head API for Canned Estimator V2.
    *   Replace all occurrences of `tf.contrib.estimator.InMemoryEvaluatorHook`
        and `tf.contrib.estimator.make_stop_at_checkpoint_step_hook` with