message: Add warning in the deprecated Keras support API
diff: @@ -63,6 +63,7 @@ from tensorflow.contrib.tpu.python.tpu import tpu_optimizer
  from tensorflow.contrib.tpu.python.tpu import tpu_system_metadata as tpu_system_metadata_lib
  from tensorflow.core.protobuf import config_pb2
  from tensorflow.core.protobuf.tpu import compilation_result_pb2 as tpu_compilation_result
  +from tensorflow.python import tf2
  from tensorflow.python.client import session as tf_session
  from tensorflow.python.data.ops import dataset_ops
  from tensorflow.python.data.ops import iterator_ops
  @@ -206,7 +207,16 @@ class TPUDistributionStrategy(object):
  Raises:
  Exception: No TPU Found on the given worker.
  """
  -
  + if tf2.enabled():
  + raise RuntimeError(
  + 'Keras support is now deprecated in support of TPU Strategy. '
  + 'Please follow the distribution strategy guide on tensorflow.org '
  + 'to migrate to the 2.0 supported version.')
  + else:
  + logging.warning(
  + 'Keras support is now deprecated in support of TPU Strategy. '
  + 'Please follow the distribution strategy guide on tensorflow.org '
  + 'to migrate to the 2.0 supported version.')
  if tpu_cluster_resolver is None:
  tpu_cluster_resolver = tpu_cluster_resolver_lib.TPUClusterResolver('')
  @@ -1373,7 +1383,16 @@ class KerasTPUModel(models.Model):
  outputs=cpu_model.outputs,
  name=cpu_model.name,
  )
  -
  + if tf2.enabled():
  + raise RuntimeError(
  + 'Keras support is now deprecated in support of TPU Strategy. '
  + 'Please follow the distribution strategy guide on tensorflow.org '
  + 'to migrate to the 2.0 supported version.')
  + else:
  + logging.warning(
  + 'Keras support is now deprecated in support of TPU Strategy. '
  + 'Please follow the distribution strategy guide on tensorflow.org '
  + 'to migrate to the 2.0 supported version.')
  # Create a mapping from numpy arrays to infeed managers.
  # Note: uses a list of tuples instead of a map because numpy arrays are
  # not hashable.
  