From cba4741d1036356971846922347edcf24fccd4d3 Mon Sep 17 00:00:00 2001
From: D-X-Y <280835372@qq.com>
Date: Sun, 5 Jul 2020 23:19:25 +0000
Subject: [PATCH] Remove TF codes

---
 exps/experimental/test-ww-bench.py            |   2 +-
 lib/tf_models/__init__.py                     |  32 --
 lib/tf_models/cell_operations.py              | 150 -------
 lib/tf_models/cell_searchs/__init__.py        |   8 -
 lib/tf_models/cell_searchs/search_cells.py    |  50 ---
 .../cell_searchs/search_model_darts.py        |  83 ----
 .../cell_searchs/search_model_gdas.py         |  99 ----
 lib/tf_optimizers/__init__.py                 |   1 -
 lib/tf_optimizers/weight_decay_optimizers.py  | 422 ------------------
 9 files changed, 1 insertion(+), 846 deletions(-)
 delete mode 100644 lib/tf_models/__init__.py
 delete mode 100644 lib/tf_models/cell_operations.py
 delete mode 100644 lib/tf_models/cell_searchs/__init__.py
 delete mode 100644 lib/tf_models/cell_searchs/search_cells.py
 delete mode 100644 lib/tf_models/cell_searchs/search_model_darts.py
 delete mode 100644 lib/tf_models/cell_searchs/search_model_gdas.py
 delete mode 100644 lib/tf_optimizers/__init__.py
 delete mode 100644 lib/tf_optimizers/weight_decay_optimizers.py

diff --git a/exps/experimental/test-ww-bench.py b/exps/experimental/test-ww-bench.py
index 4351571..a07dfa0 100644
--- a/exps/experimental/test-ww-bench.py
+++ b/exps/experimental/test-ww-bench.py
@@ -70,7 +70,7 @@ def evaluate(api, weight_dir, data: str):
       ok += 1
       norms.append(cur_norm)
     # query the accuracy
-    info = meta_info.get_metrics(data, 'ori-test', iepoch=None, is_random=777)
+    info = meta_info.get_metrics(data, 'ori-test', iepoch=None, is_random=888 if isinstance(api, NASBench201API) else 777)
     accuracies.append(info['accuracy'])
     del net, meta_info
     # print the information
diff --git a/lib/tf_models/__init__.py b/lib/tf_models/__init__.py
deleted file mode 100644
index d402913..0000000
--- a/lib/tf_models/__init__.py
+++ /dev/null
@@ -1,32 +0,0 @@
-##################################################
-# Copyright (c) Xuanyi Dong [GitHub D-X-Y], 2019 #
-##################################################
-import torch
-from os import path as osp
-
-__all__ = ['get_cell_based_tiny_net', 'get_search_spaces']
-
-
-# the cell-based NAS models
-def get_cell_based_tiny_net(config):
-  group_names = ['GDAS', 'DARTS']
-  if config.name in group_names:
-    from .cell_searchs import nas_super_nets
-    from .cell_operations import SearchSpaceNames
-    if isinstance(config.space, str): search_space = SearchSpaceNames[config.space]
-    else: search_space = config.space
-    return nas_super_nets[config.name](
-                  config.C, config.N, config.max_nodes,
-                  config.num_classes, search_space, config.affine)
-  else:
-    raise ValueError('invalid network name : {:}'.format(config.name))
-
-
-# obtain the search space, i.e., a dict mapping the operation name into a python-function for this op
-def get_search_spaces(xtype, name):
-  if xtype == 'cell':
-    from .cell_operations import SearchSpaceNames
-    assert name in SearchSpaceNames, 'invalid name [{:}] in {:}'.format(name, SearchSpaceNames.keys())
-    return SearchSpaceNames[name]
-  else:
-    raise ValueError('invalid search-space type is {:}'.format(xtype))
diff --git a/lib/tf_models/cell_operations.py b/lib/tf_models/cell_operations.py
deleted file mode 100644
index 78f1c2a..0000000
--- a/lib/tf_models/cell_operations.py
+++ /dev/null
@@ -1,150 +0,0 @@
-##################################################
-# Copyright (c) Xuanyi Dong [GitHub D-X-Y], 2019 #
-##################################################
-import tensorflow as tf
-
-__all__ = ['OPS', 'ResNetBasicblock', 'SearchSpaceNames']
-
-OPS = {
-  'none'        : lambda C_in, C_out, stride, affine: Zero(C_in, C_out, stride),
-  'avg_pool_3x3': lambda C_in, C_out, stride, affine: POOLING(C_in, C_out, stride, 'avg', affine),
-  'nor_conv_1x1': lambda C_in, C_out, stride, affine: ReLUConvBN(C_in, C_out, 1, stride, affine),
-  'nor_conv_3x3': lambda C_in, C_out, stride, affine: ReLUConvBN(C_in, C_out, 3, stride, affine),
-  'nor_conv_5x5': lambda C_in, C_out, stride, affine: ReLUConvBN(C_in, C_out, 5, stride, affine),
-  'skip_connect': lambda C_in, C_out, stride, affine: Identity(C_in, C_out, stride) if stride == 1 and C_in == C_out else FactorizedReduce(C_in, C_out, stride, affine)
-}
-
-NAS_BENCH_201         = ['none', 'skip_connect', 'nor_conv_1x1', 'nor_conv_3x3', 'avg_pool_3x3']
-
-SearchSpaceNames = {
-                    'nas-bench-201': NAS_BENCH_201,
-                   }
-
-
-class POOLING(tf.keras.layers.Layer):
-
-  def __init__(self, C_in, C_out, stride, mode, affine):
-    super(POOLING, self).__init__()
-    if C_in == C_out:
-      self.preprocess = None
-    else:
-      self.preprocess = ReLUConvBN(C_in, C_out, 1, 1, affine)
-    if mode == 'avg'  : self.op = tf.keras.layers.AvgPool2D((3,3), strides=stride, padding='same')
-    elif mode == 'max': self.op = tf.keras.layers.MaxPool2D((3,3), strides=stride, padding='same')
-    else              : raise ValueError('Invalid mode={:} in POOLING'.format(mode))
-
-  def call(self, inputs, training):
-    if self.preprocess: x = self.preprocess(inputs)
-    else              : x = inputs
-    return self.op(x)
-
-
-class Identity(tf.keras.layers.Layer):
-  def __init__(self, C_in, C_out, stride):
-    super(Identity, self).__init__()
-    if C_in != C_out or stride != 1:
-      self.layer = tf.keras.layers.Conv2D(C_out, 3, stride, padding='same', use_bias=False)
-    else:
-      self.layer = None
-  
-  def call(self, inputs, training):
-    x = inputs
-    if self.layer is not None:
-      x = self.layer(x)
-    return x
-
-
-
-class Zero(tf.keras.layers.Layer):
-  def __init__(self, C_in, C_out, stride):
-    super(Zero, self).__init__()
-    if C_in != C_out:
-      self.layer = tf.keras.layers.Conv2D(C_out, 1, stride, padding='same', use_bias=False)
-    elif stride != 1:
-      self.layer = tf.keras.layers.AvgPool2D((stride,stride), None, padding="same")
-    else:
-      self.layer = None
-  
-  def call(self, inputs, training):
-    x = tf.zeros_like(inputs)
-    if self.layer is not None:
-      x = self.layer(x)
-    return x
-
-
-class ReLUConvBN(tf.keras.layers.Layer):
-  def __init__(self, C_in, C_out, kernel_size, strides, affine):
-    super(ReLUConvBN, self).__init__()
-    self.C_in = C_in
-    self.relu = tf.keras.activations.relu
-    self.conv = tf.keras.layers.Conv2D(C_out, kernel_size, strides, padding='same', use_bias=False)
-    self.bn   = tf.keras.layers.BatchNormalization(center=affine, scale=affine)
-  
-  def call(self, inputs, training):
-    x = self.relu(inputs)
-    x = self.conv(x)
-    x = self.bn(x, training)
-    return x
-
-
-class FactorizedReduce(tf.keras.layers.Layer):
-  def __init__(self, C_in, C_out, stride, affine):
-    assert output_filters % 2 == 0, ('Need even number of filters when using this factorized reduction.')
-    self.stride == stride
-    self.relu   = tf.keras.activations.relu
-    if stride == 1:
-      self.layer = tf.keras.Sequential([
-                          tf.keras.layers.Conv2D(C_out, 1, strides, padding='same', use_bias=False),
-                          tf.keras.layers.BatchNormalization(center=affine, scale=affine)])
-    elif stride == 2:
-      stride_spec = [1, stride, stride, 1] # data_format == 'NHWC'
-      self.layer1 = tf.keras.layers.Conv2D(C_out//2, 1, strides, padding='same', use_bias=False)
-      self.layer2 = tf.keras.layers.Conv2D(C_out//2, 1, strides, padding='same', use_bias=False)
-      self.bn     = tf.keras.layers.BatchNormalization(center=affine, scale=affine)
-    else:
-      raise ValueError('invalid stride={:}'.format(stride))
-
-  def call(self, inputs, training):
-    x = self.relu(inputs)
-    if self.stride == 1:
-      return self.layer(x, training)
-    else:
-      path1 = x
-      path2 = tf.pad(x, [[0, 0], [0, 1], [0, 1], [0, 0]])[:, 1:, 1:, :] # data_format == 'NHWC'
-      x1 = self.layer1(path1)
-      x2 = self.layer2(path2)
-      final_path = tf.concat(values=[x1, x2], axis=3)
-      return self.bn(final_path)
-
-
-class ResNetBasicblock(tf.keras.layers.Layer):
-
-  def __init__(self, inplanes, planes, stride, affine=True):
-    super(ResNetBasicblock, self).__init__()
-    assert stride == 1 or stride == 2, 'invalid stride {:}'.format(stride)
-    self.conv_a = ReLUConvBN(inplanes, planes, 3, stride, affine)
-    self.conv_b = ReLUConvBN(  planes, planes, 3,      1, affine)
-    if stride == 2:
-      self.downsample = tf.keras.Sequential([
-                                tf.keras.layers.AvgPool2D((stride,stride), None, padding="same"),
-                                tf.keras.layers.Conv2D(planes, 1, 1, padding='same', use_bias=False)])
-    elif inplanes != planes:
-      self.downsample = ReLUConvBN(inplanes, planes, 1, stride, affine)
-    else:
-      self.downsample = None
-    self.addition = tf.keras.layers.Add()
-    self.in_dim  = inplanes
-    self.out_dim = planes
-    self.stride  = stride
-    self.num_conv = 2
-
-  def call(self, inputs, training):
-
-    basicblock = self.conv_a(inputs, training)
-    basicblock = self.conv_b(basicblock, training)
-
-    if self.downsample is not None:
-      residual = self.downsample(inputs)
-    else:
-      residual = inputs
-    return self.addition([residual, basicblock])
diff --git a/lib/tf_models/cell_searchs/__init__.py b/lib/tf_models/cell_searchs/__init__.py
deleted file mode 100644
index 717fbe4..0000000
--- a/lib/tf_models/cell_searchs/__init__.py
+++ /dev/null
@@ -1,8 +0,0 @@
-##################################################
-# Copyright (c) Xuanyi Dong [GitHub D-X-Y], 2019 #
-##################################################
-from .search_model_gdas     import TinyNetworkGDAS
-from .search_model_darts    import TinyNetworkDARTS
-
-nas_super_nets = {'GDAS' : TinyNetworkGDAS,
-                  'DARTS': TinyNetworkDARTS}
diff --git a/lib/tf_models/cell_searchs/search_cells.py b/lib/tf_models/cell_searchs/search_cells.py
deleted file mode 100644
index 83de6b3..0000000
--- a/lib/tf_models/cell_searchs/search_cells.py
+++ /dev/null
@@ -1,50 +0,0 @@
-##################################################
-# Copyright (c) Xuanyi Dong [GitHub D-X-Y], 2019 #
-##################################################
-import math, random
-import tensorflow as tf
-from copy import deepcopy
-from ..cell_operations import OPS
-
-
-class NAS201SearchCell(tf.keras.layers.Layer):
-
-  def __init__(self, C_in, C_out, stride, max_nodes, op_names, affine=False):
-    super(NAS201SearchCell, self).__init__()
-
-    self.op_names  = deepcopy(op_names)
-    self.max_nodes = max_nodes
-    self.in_dim    = C_in
-    self.out_dim   = C_out
-    self.edge_keys = []
-    for i in range(1, max_nodes):
-      for j in range(i):
-        node_str = '{:}<-{:}'.format(i, j)
-        if j == 0:
-          xlists = [OPS[op_name](C_in , C_out, stride, affine) for op_name in op_names]
-        else:
-          xlists = [OPS[op_name](C_in , C_out,      1, affine) for op_name in op_names]
-        for k, op in enumerate(xlists):
-          setattr(self, '{:}.{:}'.format(node_str, k), op)
-        self.edge_keys.append( node_str )
-    self.edge_keys  = sorted(self.edge_keys)
-    self.edge2index = {key:i for i, key in enumerate(self.edge_keys)}
-    self.num_edges  = len(self.edge_keys)
-
-  def call(self, inputs, weightss, training):
-    w_lst = tf.split(weightss, self.num_edges, 0)
-    nodes = [inputs]
-    for i in range(1, self.max_nodes):
-      inter_nodes = []
-      for j in range(i):
-        node_str = '{:}<-{:}'.format(i, j)
-        edge_idx = self.edge2index[node_str]
-        op_outps = []
-        for k, op_name in enumerate(self.op_names):
-          op = getattr(self, '{:}.{:}'.format(node_str, k))
-          op_outps.append( op(nodes[j], training) )
-        stack_op_outs = tf.stack(op_outps, axis=-1)
-        weighted_sums = tf.math.multiply(stack_op_outs, w_lst[edge_idx])
-        inter_nodes.append( tf.math.reduce_sum(weighted_sums, axis=-1) )
-      nodes.append( tf.math.add_n(inter_nodes) )
-    return nodes[-1]
diff --git a/lib/tf_models/cell_searchs/search_model_darts.py b/lib/tf_models/cell_searchs/search_model_darts.py
deleted file mode 100644
index ad05b8b..0000000
--- a/lib/tf_models/cell_searchs/search_model_darts.py
+++ /dev/null
@@ -1,83 +0,0 @@
-import tensorflow as tf
-import numpy as np
-from copy import deepcopy
-from ..cell_operations import ResNetBasicblock
-from .search_cells     import NAS201SearchCell as SearchCell
-
-
-class TinyNetworkDARTS(tf.keras.Model):
-
-  def __init__(self, C, N, max_nodes, num_classes, search_space, affine):
-    super(TinyNetworkDARTS, self).__init__()
-    self._C        = C
-    self._layerN   = N
-    self.max_nodes = max_nodes
-    self.stem = tf.keras.Sequential([
-                    tf.keras.layers.Conv2D(16, 3, 1, padding='same', use_bias=False),
-                    tf.keras.layers.BatchNormalization()], name='stem')
-  
-    layer_channels   = [C    ] * N + [C*2 ] + [C*2  ] * N + [C*4 ] + [C*4  ] * N    
-    layer_reductions = [False] * N + [True] + [False] * N + [True] + [False] * N
-
-    C_prev, num_edge, edge2index = C, None, None
-    for index, (C_curr, reduction) in enumerate(zip(layer_channels, layer_reductions)):
-      cell_prefix = 'cell-{:03d}'.format(index)
-      #with tf.name_scope(cell_prefix) as scope:
-      if reduction:
-        cell = ResNetBasicblock(C_prev, C_curr, 2)
-      else:
-        cell = SearchCell(C_prev, C_curr, 1, max_nodes, search_space, affine)
-        if num_edge is None: num_edge, edge2index = cell.num_edges, cell.edge2index
-        else: assert num_edge == cell.num_edges and edge2index == cell.edge2index, 'invalid {:} vs. {:}.'.format(num_edge, cell.num_edges)
-      C_prev = cell.out_dim
-      setattr(self, cell_prefix, cell)
-    self.num_layers = len(layer_reductions)
-    self.op_names   = deepcopy( search_space )
-    self.edge2index = edge2index
-    self.num_edge   = num_edge
-    self.lastact    = tf.keras.Sequential([
-                        tf.keras.layers.BatchNormalization(),
-                        tf.keras.layers.ReLU(),
-                        tf.keras.layers.GlobalAvgPool2D(),
-                        tf.keras.layers.Flatten(),
-                        tf.keras.layers.Dense(num_classes, activation='softmax')], name='lastact')
-    #self.arch_parameters = nn.Parameter( 1e-3*torch.randn(num_edge, len(search_space)) )
-    arch_init = tf.random_normal_initializer(mean=0, stddev=0.001)
-    self.arch_parameters = tf.Variable(initial_value=arch_init(shape=(num_edge, len(search_space)), dtype='float32'), trainable=True, name='arch-encoding')
-
-  def get_alphas(self):
-    xlist = self.trainable_variables
-    return [x for x in xlist if 'arch-encoding' in x.name]
-
-  def get_weights(self):
-    xlist = self.trainable_variables
-    return [x for x in xlist if 'arch-encoding' not in x.name]
-
-  def get_np_alphas(self):
-    arch_nps = self.arch_parameters.numpy()
-    arch_ops = np.exp(arch_nps) / np.sum(np.exp(arch_nps), axis=-1, keepdims=True)
-    return arch_ops
-
-  def genotype(self):
-    genotypes, arch_nps = [], self.arch_parameters.numpy()
-    for i in range(1, self.max_nodes):
-      xlist = []
-      for j in range(i):
-        node_str = '{:}<-{:}'.format(i, j)
-        weights = arch_nps[ self.edge2index[node_str] ]
-        op_name = self.op_names[ weights.argmax().item() ]
-        xlist.append((op_name, j))
-      genotypes.append( tuple(xlist) )
-    return genotypes
-
-  def call(self, inputs, training):
-    weightss = tf.nn.softmax(self.arch_parameters, axis=1)
-    feature = self.stem(inputs, training)
-    for idx in range(self.num_layers):
-      cell = getattr(self, 'cell-{:03d}'.format(idx))
-      if isinstance(cell, SearchCell):
-        feature = cell.call(feature, weightss, training)
-      else:
-        feature = cell(feature, training)
-    logits = self.lastact(feature, training)
-    return logits
diff --git a/lib/tf_models/cell_searchs/search_model_gdas.py b/lib/tf_models/cell_searchs/search_model_gdas.py
deleted file mode 100644
index d10bb19..0000000
--- a/lib/tf_models/cell_searchs/search_model_gdas.py
+++ /dev/null
@@ -1,99 +0,0 @@
-###########################################################################
-# Searching for A Robust Neural Architecture in Four GPU Hours, CVPR 2019 #
-###########################################################################
-import tensorflow as tf
-import numpy as np
-from copy import deepcopy
-from ..cell_operations import ResNetBasicblock
-from .search_cells     import NAS201SearchCell as SearchCell
-
-
-def sample_gumbel(shape, eps=1e-20):
-  U = tf.random.uniform(shape, minval=0, maxval=1)
-  return -tf.math.log(-tf.math.log(U + eps) + eps)
-
-
-def gumbel_softmax(logits, temperature):
-  gumbel_softmax_sample = logits + sample_gumbel(tf.shape(logits))
-  y = tf.nn.softmax(gumbel_softmax_sample / temperature)
-  return y
-
-
-class TinyNetworkGDAS(tf.keras.Model):
-
-  def __init__(self, C, N, max_nodes, num_classes, search_space, affine):
-    super(TinyNetworkGDAS, self).__init__()
-    self._C        = C
-    self._layerN   = N
-    self.max_nodes = max_nodes
-    self.stem = tf.keras.Sequential([
-                    tf.keras.layers.Conv2D(16, 3, 1, padding='same', use_bias=False),
-                    tf.keras.layers.BatchNormalization()], name='stem')
-  
-    layer_channels   = [C    ] * N + [C*2 ] + [C*2  ] * N + [C*4 ] + [C*4  ] * N    
-    layer_reductions = [False] * N + [True] + [False] * N + [True] + [False] * N
-
-    C_prev, num_edge, edge2index = C, None, None
-    for index, (C_curr, reduction) in enumerate(zip(layer_channels, layer_reductions)):
-      cell_prefix = 'cell-{:03d}'.format(index)
-      #with tf.name_scope(cell_prefix) as scope:
-      if reduction:
-        cell = ResNetBasicblock(C_prev, C_curr, 2)
-      else:
-        cell = SearchCell(C_prev, C_curr, 1, max_nodes, search_space, affine)
-        if num_edge is None: num_edge, edge2index = cell.num_edges, cell.edge2index
-        else: assert num_edge == cell.num_edges and edge2index == cell.edge2index, 'invalid {:} vs. {:}.'.format(num_edge, cell.num_edges)
-      C_prev = cell.out_dim
-      setattr(self, cell_prefix, cell)
-    self.num_layers = len(layer_reductions)
-    self.op_names   = deepcopy( search_space )
-    self.edge2index = edge2index
-    self.num_edge   = num_edge
-    self.lastact    = tf.keras.Sequential([
-                        tf.keras.layers.BatchNormalization(),
-                        tf.keras.layers.ReLU(),
-                        tf.keras.layers.GlobalAvgPool2D(),
-                        tf.keras.layers.Flatten(),
-                        tf.keras.layers.Dense(num_classes, activation='softmax')], name='lastact')
-    #self.arch_parameters = nn.Parameter( 1e-3*torch.randn(num_edge, len(search_space)) )
-    arch_init = tf.random_normal_initializer(mean=0, stddev=0.001)
-    self.arch_parameters = tf.Variable(initial_value=arch_init(shape=(num_edge, len(search_space)), dtype='float32'), trainable=True, name='arch-encoding')
-
-  def get_alphas(self):
-    xlist = self.trainable_variables
-    return [x for x in xlist if 'arch-encoding' in x.name]
-
-  def get_weights(self):
-    xlist = self.trainable_variables
-    return [x for x in xlist if 'arch-encoding' not in x.name]
-
-  def get_np_alphas(self):
-    arch_nps = self.arch_parameters.numpy()
-    arch_ops = np.exp(arch_nps) / np.sum(np.exp(arch_nps), axis=-1, keepdims=True)
-    return arch_ops
-
-  def genotype(self):
-    genotypes, arch_nps = [], self.arch_parameters.numpy()
-    for i in range(1, self.max_nodes):
-      xlist = []
-      for j in range(i):
-        node_str = '{:}<-{:}'.format(i, j)
-        weights = arch_nps[ self.edge2index[node_str] ]
-        op_name = self.op_names[ weights.argmax().item() ]
-        xlist.append((op_name, j))
-      genotypes.append( tuple(xlist) )
-    return genotypes
-
-  # 
-  def call(self, inputs, tau, training):
-    weightss = tf.cond(tau < 0, lambda: tf.nn.softmax(self.arch_parameters, axis=1),
-                                lambda: gumbel_softmax(tf.math.log_softmax(self.arch_parameters, axis=1), tau))
-    feature = self.stem(inputs, training)
-    for idx in range(self.num_layers):
-      cell = getattr(self, 'cell-{:03d}'.format(idx))
-      if isinstance(cell, SearchCell):
-        feature = cell.call(feature, weightss, training)
-      else:
-        feature = cell(feature, training)
-    logits = self.lastact(feature, training)
-    return logits
diff --git a/lib/tf_optimizers/__init__.py b/lib/tf_optimizers/__init__.py
deleted file mode 100644
index c72fe17..0000000
--- a/lib/tf_optimizers/__init__.py
+++ /dev/null
@@ -1 +0,0 @@
-from .weight_decay_optimizers import AdamW, SGDW
diff --git a/lib/tf_optimizers/weight_decay_optimizers.py b/lib/tf_optimizers/weight_decay_optimizers.py
deleted file mode 100644
index b4e72dc..0000000
--- a/lib/tf_optimizers/weight_decay_optimizers.py
+++ /dev/null
@@ -1,422 +0,0 @@
-# Copyright 2019 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.
-# ==============================================================================
-"""Base class to make optimizers weight decay ready."""
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-
-import tensorflow as tf
-
-
-class DecoupledWeightDecayExtension(object):
-    """This class allows to extend optimizers with decoupled weight decay.
-
-    It implements the decoupled weight decay described by Loshchilov & Hutter
-    (https://arxiv.org/pdf/1711.05101.pdf), in which the weight decay is
-    decoupled from the optimization steps w.r.t. to the loss function.
-    For SGD variants, this simplifies hyperparameter search since it decouples
-    the settings of weight decay and learning rate.
-    For adaptive gradient algorithms, it regularizes variables with large
-    gradients more than L2 regularization would, which was shown to yield
-    better training loss and generalization error in the paper above.
-
-    This class alone is not an optimizer but rather extends existing
-    optimizers with decoupled weight decay. We explicitly define the two
-    examples used in the above paper (SGDW and AdamW), but in general this
-    can extend any OptimizerX by using
-    `extend_with_decoupled_weight_decay(
-        OptimizerX, weight_decay=weight_decay)`.
-    In order for it to work, it must be the first class the Optimizer with
-    weight decay inherits from, e.g.
-
-    ```python
-    class AdamW(DecoupledWeightDecayExtension, tf.keras.optimizers.Adam):
-      def __init__(self, weight_decay, *args, **kwargs):
-        super(AdamW, self).__init__(weight_decay, *args, **kwargs).
-    ```
-
-    Note: this extension decays weights BEFORE applying the update based
-    on the gradient, i.e. this extension only has the desired behaviour for
-    optimizers which do not depend on the value of'var' in the update step!
-
-    Note: when applying a decay to the learning rate, be sure to manually apply
-    the decay to the `weight_decay` as well. For example:
-
-    ```python
-    step = tf.Variable(0, trainable=False)
-    schedule = tf.optimizers.schedules.PiecewiseConstantDecay(
-        [10000, 15000], [1e-0, 1e-1, 1e-2])
-    # lr and wd can be a function or a tensor
-    lr = 1e-1 * schedule(step)
-    wd = lambda: 1e-4 * schedule(step)
-
-    # ...
-
-    optimizer = tfa.optimizers.AdamW(learning_rate=lr, weight_decay=wd)
-    ```
-    """
-
-    def __init__(self, weight_decay, **kwargs):
-        """Extension class that adds weight decay to an optimizer.
-
-        Args:
-            weight_decay: A `Tensor` or a floating point value, the factor by
-                which a variable is decayed in the update step.
-            **kwargs: Optional list or tuple or set of `Variable` objects to
-                decay.
-        """
-        wd = kwargs.pop('weight_decay', weight_decay)
-        super(DecoupledWeightDecayExtension, self).__init__(**kwargs)
-        self._decay_var_list = None  # is set in minimize or apply_gradients
-        self._set_hyper('weight_decay', wd)
-
-    def get_config(self):
-        config = super(DecoupledWeightDecayExtension, self).get_config()
-        config.update({
-            'weight_decay':
-            self._serialize_hyperparameter('weight_decay'),
-        })
-        return config
-
-    def minimize(self,
-                 loss,
-                 var_list,
-                 grad_loss=None,
-                 name=None,
-                 decay_var_list=None):
-        """Minimize `loss` by updating `var_list`.
-
-        This method simply computes gradient using `tf.GradientTape` and calls
-        `apply_gradients()`. If you want to process the gradient before
-        applying then call `tf.GradientTape` and `apply_gradients()` explicitly
-        instead of using this function.
-
-        Args:
-            loss: A callable taking no arguments which returns the value to
-                minimize.
-            var_list: list or tuple of `Variable` objects to update to
-                minimize `loss`, or a callable returning the list or tuple of
-                `Variable` objects. Use callable when the variable list would
-                otherwise be incomplete before `minimize` since the variables
-                are created at the first time `loss` is called.
-            grad_loss: Optional. A `Tensor` holding the gradient computed for
-                `loss`.
-            decay_var_list: Optional list of variables to be decayed. Defaults
-                to all variables in var_list.
-            name: Optional name for the returned operation.
-        Returns:
-            An Operation that updates the variables in `var_list`.  If
-            `global_step` was not `None`, that operation also increments
-            `global_step`.
-        Raises:
-            ValueError: If some of the variables are not `Variable` objects.
-        """
-        self._decay_var_list = set(decay_var_list) if decay_var_list else False
-        return super(DecoupledWeightDecayExtension, self).minimize(
-            loss, var_list=var_list, grad_loss=grad_loss, name=name)
-
-    def apply_gradients(self, grads_and_vars, name=None, decay_var_list=None):
-        """Apply gradients to variables.
-
-        This is the second part of `minimize()`. It returns an `Operation` that
-        applies gradients.
-
-        Args:
-            grads_and_vars: List of (gradient, variable) pairs.
-            name: Optional name for the returned operation.  Default to the
-                name passed to the `Optimizer` constructor.
-            decay_var_list: Optional list of variables to be decayed. Defaults
-                to all variables in var_list.
-        Returns:
-            An `Operation` that applies the specified gradients. If
-            `global_step` was not None, that operation also increments
-            `global_step`.
-        Raises:
-            TypeError: If `grads_and_vars` is malformed.
-            ValueError: If none of the variables have gradients.
-        """
-        self._decay_var_list = set(decay_var_list) if decay_var_list else False
-        return super(DecoupledWeightDecayExtension, self).apply_gradients(
-            grads_and_vars, name=name)
-
-    def _decay_weights_op(self, var):
-        if not self._decay_var_list or var in self._decay_var_list:
-            return var.assign_sub(
-                self._get_hyper('weight_decay', var.dtype) * var,
-                self._use_locking)
-        return tf.no_op()
-
-    def _decay_weights_sparse_op(self, var, indices):
-        if not self._decay_var_list or var in self._decay_var_list:
-            update = (-self._get_hyper('weight_decay', var.dtype) * tf.gather(
-                var, indices))
-            return self._resource_scatter_add(var, indices, update)
-        return tf.no_op()
-
-    # Here, we overwrite the apply functions that the base optimizer calls.
-    # super().apply_x resolves to the apply_x function of the BaseOptimizer.
-
-    def _resource_apply_dense(self, grad, var):
-        with tf.control_dependencies([self._decay_weights_op(var)]):
-            return super(DecoupledWeightDecayExtension,
-                         self)._resource_apply_dense(grad, var)
-
-    def _resource_apply_sparse(self, grad, var, indices):
-        decay_op = self._decay_weights_sparse_op(var, indices)
-        with tf.control_dependencies([decay_op]):
-            return super(DecoupledWeightDecayExtension,
-                         self)._resource_apply_sparse(grad, var, indices)
-
-
-def extend_with_decoupled_weight_decay(base_optimizer):
-    """Factory function returning an optimizer class with decoupled weight
-    decay.
-
-    Returns an optimizer class. An instance of the returned class computes the
-    update step of `base_optimizer` and additionally decays the weights.
-    E.g., the class returned by
-    `extend_with_decoupled_weight_decay(tf.keras.optimizers.Adam)` is
-    equivalent to `tfa.optimizers.AdamW`.
-
-    The API of the new optimizer class slightly differs from the API of the
-    base optimizer:
-    - The first argument to the constructor is the weight decay rate.
-    - `minimize` and `apply_gradients` accept the optional keyword argument
-      `decay_var_list`, which specifies the variables that should be decayed.
-      If `None`, all variables that are optimized are decayed.
-
-    Usage example:
-    ```python
-    # MyAdamW is a new class
-    MyAdamW = extend_with_decoupled_weight_decay(tf.keras.optimizers.Adam)
-    # Create a MyAdamW object
-    optimizer = MyAdamW(weight_decay=0.001, learning_rate=0.001)
-    # update var1, var2 but only decay var1
-    optimizer.minimize(loss, var_list=[var1, var2], decay_variables=[var1])
-
-    Note: this extension decays weights BEFORE applying the update based
-    on the gradient, i.e. this extension only has the desired behaviour for
-    optimizers which do not depend on the value of 'var' in the update step!
-
-    Note: when applying a decay to the learning rate, be sure to manually apply
-    the decay to the `weight_decay` as well. For example:
-
-    ```python
-    step = tf.Variable(0, trainable=False)
-    schedule = tf.optimizers.schedules.PiecewiseConstantDecay(
-        [10000, 15000], [1e-0, 1e-1, 1e-2])
-    # lr and wd can be a function or a tensor
-    lr = 1e-1 * schedule(step)
-    wd = lambda: 1e-4 * schedule(step)
-
-    # ...
-
-    optimizer = tfa.optimizers.AdamW(learning_rate=lr, weight_decay=wd)
-    ```
-
-    Note: you might want to register your own custom optimizer using
-    `tf.keras.utils.get_custom_objects()`.
-
-    Args:
-        base_optimizer: An optimizer class that inherits from
-            tf.optimizers.Optimizer.
-
-    Returns:
-        A new optimizer class that inherits from DecoupledWeightDecayExtension
-        and base_optimizer.
-    """
-
-    class OptimizerWithDecoupledWeightDecay(DecoupledWeightDecayExtension,
-                                            base_optimizer):
-        """Base_optimizer with decoupled weight decay.
-
-        This class computes the update step of `base_optimizer` and
-        additionally decays the variable with the weight decay being
-        decoupled from the optimization steps w.r.t. to the loss
-        function, as described by Loshchilov & Hutter
-        (https://arxiv.org/pdf/1711.05101.pdf). For SGD variants, this
-        simplifies hyperparameter search since it decouples the settings
-        of weight decay and learning rate. For adaptive gradient
-        algorithms, it regularizes variables with large gradients more
-        than L2 regularization would, which was shown to yield better
-        training loss and generalization error in the paper above.
-        """
-
-        def __init__(self, weight_decay, *args, **kwargs):
-            # super delegation is necessary here
-            super(OptimizerWithDecoupledWeightDecay, self).__init__(
-                weight_decay, *args, **kwargs)
-
-    return OptimizerWithDecoupledWeightDecay
-
-
-class SGDW(DecoupledWeightDecayExtension, tf.keras.optimizers.SGD):
-    """Optimizer that implements the Momentum algorithm with weight_decay.
-
-    This is an implementation of the SGDW optimizer described in "Decoupled
-    Weight Decay Regularization" by Loshchilov & Hutter
-    (https://arxiv.org/abs/1711.05101)
-    ([pdf])(https://arxiv.org/pdf/1711.05101.pdf).
-    It computes the update step of `tf.keras.optimizers.SGD` and additionally
-    decays the variable. Note that this is different from adding
-    L2 regularization on the variables to the loss. Decoupling the weight decay
-    from other hyperparameters (in particular the learning rate) simplifies
-    hyperparameter search.
-
-    For further information see the documentation of the SGD Optimizer.
-
-    This optimizer can also be instantiated as
-    ```python
-    extend_with_decoupled_weight_decay(tf.keras.optimizers.SGD,
-                                       weight_decay=weight_decay)
-    ```
-
-    Note: when applying a decay to the learning rate, be sure to manually apply
-    the decay to the `weight_decay` as well. For example:
-
-    ```python
-    step = tf.Variable(0, trainable=False)
-    schedule = tf.optimizers.schedules.PiecewiseConstantDecay(
-        [10000, 15000], [1e-0, 1e-1, 1e-2])
-    # lr and wd can be a function or a tensor
-    lr = 1e-1 * schedule(step)
-    wd = lambda: 1e-4 * schedule(step)
-
-    # ...
-
-    optimizer = tfa.optimizers.SGDW(
-        learning_rate=lr, weight_decay=wd, momentum=0.9)
-    ```
-    """
-
-    def __init__(self,
-                 weight_decay,
-                 learning_rate=0.001,
-                 momentum=0.0,
-                 nesterov=False,
-                 name='SGDW',
-                 **kwargs):
-        """Construct a new SGDW optimizer.
-
-        For further information see the documentation of the SGD Optimizer.
-
-        Args:
-            learning_rate: float hyperparameter >= 0. Learning rate.
-            momentum: float hyperparameter >= 0 that accelerates SGD in the
-                relevant direction and dampens oscillations.
-            nesterov: boolean. Whether to apply Nesterov momentum.
-            name: Optional name prefix for the operations created when applying
-                gradients.  Defaults to 'SGD'.
-            **kwargs: keyword arguments. Allowed to be {`clipnorm`,
-                `clipvalue`, `lr`, `decay`}. `clipnorm` is clip gradients by
-                norm; `clipvalue` is clip gradients by value, `decay` is
-                included for backward compatibility to allow time inverse decay
-                of learning rate. `lr` is included for backward compatibility,
-                recommended to use `learning_rate` instead.
-        """
-        super(SGDW, self).__init__(
-            weight_decay,
-            learning_rate=learning_rate,
-            momentum=momentum,
-            nesterov=nesterov,
-            name=name,
-            **kwargs)
-
-
-class AdamW(DecoupledWeightDecayExtension, tf.keras.optimizers.Adam):
-    """Optimizer that implements the Adam algorithm with weight decay.
-
-    This is an implementation of the AdamW optimizer described in "Decoupled
-    Weight Decay Regularization" by Loshchilov & Hutter
-    (https://arxiv.org/abs/1711.05101)
-    ([pdf])(https://arxiv.org/pdf/1711.05101.pdf).
-
-    It computes the update step of `tf.keras.optimizers.Adam` and additionally
-    decays the variable. Note that this is different from adding L2
-    regularization on the variables to the loss: it regularizes variables with
-    large gradients more than L2 regularization would, which was shown to yield
-    better training loss and generalization error in the paper above.
-
-    For further information see the documentation of the Adam Optimizer.
-
-    This optimizer can also be instantiated as
-    ```python
-    extend_with_decoupled_weight_decay(tf.keras.optimizers.Adam,
-                                       weight_decay=weight_decay)
-    ```
-
-    Note: when applying a decay to the learning rate, be sure to manually apply
-    the decay to the `weight_decay` as well. For example:
-
-    ```python
-    step = tf.Variable(0, trainable=False)
-    schedule = tf.optimizers.schedules.PiecewiseConstantDecay(
-        [10000, 15000], [1e-0, 1e-1, 1e-2])
-    # lr and wd can be a function or a tensor
-    lr = 1e-1 * schedule(step)
-    wd = lambda: 1e-4 * schedule(step)
-
-    # ...
-
-    optimizer = tfa.optimizers.AdamW(learning_rate=lr, weight_decay=wd)
-    ```
-    """
-
-    def __init__(self,
-                 weight_decay,
-                 learning_rate=0.001,
-                 beta_1=0.9,
-                 beta_2=0.999,
-                 epsilon=1e-07,
-                 amsgrad=False,
-                 name="AdamW",
-                 **kwargs):
-        """Construct a new AdamW optimizer.
-
-        For further information see the documentation of the Adam Optimizer.
-
-        Args:
-            weight_decay: A Tensor or a floating point value. The weight decay.
-            learning_rate: A Tensor or a floating point value. The learning
-                rate.
-            beta_1: A float value or a constant float tensor. The exponential
-                decay rate for the 1st moment estimates.
-            beta_2: A float value or a constant float tensor. The exponential
-                decay rate for the 2nd moment estimates.
-            epsilon: A small constant for numerical stability. This epsilon is
-                "epsilon hat" in the Kingma and Ba paper (in the formula just
-                before Section 2.1), not the epsilon in Algorithm 1 of the
-                paper.
-            amsgrad: boolean. Whether to apply AMSGrad variant of this
-                algorithm from the paper "On the Convergence of Adam and
-                beyond".
-            name: Optional name for the operations created when applying
-                gradients. Defaults to "AdamW".
-            **kwargs: keyword arguments. Allowed to be {`clipnorm`,
-                `clipvalue`, `lr`, `decay`}. `clipnorm` is clip gradients by
-                norm; `clipvalue` is clip gradients by value, `decay` is
-                included for backward compatibility to allow time inverse decay
-                of learning rate. `lr` is included for backward compatibility,
-                recommended to use `learning_rate` instead.
-        """
-        super(AdamW, self).__init__(
-            weight_decay,
-            learning_rate=learning_rate,
-            beta_1=beta_1,
-            beta_2=beta_2,
-            epsilon=epsilon,
-            amsgrad=amsgrad,
-            name=name,
-            **kwargs)