text: # Copyright 2016 The TensorFlow Authors. All Rights Reserved.
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  #     http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  # ==============================================================================
  """Keras built-in optimizers."""
  
  from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  
  # Optimizer classes.
  from tensorflow.python.keras.optimizers import Adadelta
  from tensorflow.python.keras.optimizers import Adagrad
  from tensorflow.python.keras.optimizers import Adam
  from tensorflow.python.keras.optimizers import Adamax
  from tensorflow.python.keras.optimizers import Nadam
  from tensorflow.python.keras.optimizers import Optimizer
  from tensorflow.python.keras.optimizers import RMSprop
  from tensorflow.python.keras.optimizers import SGD
  
  # Auxiliary utils.
  # pylint: disable=g-bad-import-order
  from tensorflow.python.keras.optimizers import deserialize
  from tensorflow.python.keras.optimizers import serialize
  from tensorflow.python.keras.optimizers import get
  
  del absolute_import
  del division
  del print_function
  