Fix compatibility issues for the TF/Keras 2.13.

PiperOrigin-RevId: 535031817

tensorflow_model_optimization/python/core/quantization/keras/default_8bit/default_8bit_transforms.py

@@ -17,7 +17,6 @@
 import collections
 import inspect
 
-from keras import backend
 import numpy as np
 import tensorflow as tf
 
@@ -29,6 +28,12 @@
 from tensorflow_model_optimization.python.core.quantization.keras.default_8bit import default_8bit_quantize_registry
 from tensorflow_model_optimization.python.core.quantization.keras.graph_transformations import transforms
 
+try:
+  from keras.backend import unique_object_name  # pylint: disable=g-import-not-at-top
+except ImportError:
+  # Path as seen in pip packages as of TF/Keras 2.13.
+  from keras.src.backend import unique_object_name  # pylint: disable=g-import-not-at-top
+
 LayerNode = transforms.LayerNode
 LayerPattern = transforms.LayerPattern
 
@@ -364,9 +369,9 @@ def pattern(self):
     return LayerPattern('SeparableConv1D')
 
   def _get_name(self, prefix):
-    # TODO(pulkitb): Move away from `backend.unique_object_name` since it isn't
+    # TODO(pulkitb): Move away from `unique_object_name` since it isn't
     # exposed as externally usable.
-    return backend.unique_object_name(prefix)
+    return unique_object_name(prefix)
 
   def replacement(self, match_layer):
     if _has_custom_quantize_config(match_layer):

tensorflow_model_optimization/python/core/quantization/keras/experimental/default_n_bit/default_n_bit_transforms.py

@@ -17,7 +17,6 @@
 import collections
 import inspect
 
-from keras import backend
 import numpy as np
 import tensorflow as tf
 
@@ -29,6 +28,13 @@
 from tensorflow_model_optimization.python.core.quantization.keras.experimental.default_n_bit import default_n_bit_quantize_registry
 from tensorflow_model_optimization.python.core.quantization.keras.graph_transformations import transforms
 
+
+try:
+  from keras.backend import unique_object_name  # pylint: disable=g-import-not-at-top
+except ImportError:
+  # Path as seen in pip packages as of TF/Keras 2.13.
+  from keras.src.backend import unique_object_name  # pylint: disable=g-import-not-at-top
+
 LayerNode = transforms.LayerNode
 LayerPattern = transforms.LayerPattern
 
@@ -395,9 +401,9 @@ def pattern(self):
     return LayerPattern('SeparableConv1D')
 
   def _get_name(self, prefix):
-    # TODO(pulkitb): Move away from `backend.unique_object_name` since it isn't
+    # TODO(pulkitb): Move away from `unique_object_name` since it isn't
     # exposed as externally usable.
-    return backend.unique_object_name(prefix)
+    return unique_object_name(prefix)
 
   def replacement(self, match_layer):
     if _has_custom_quantize_config(match_layer):

tensorflow_model_optimization/python/core/sparsity/keras/prune_registry.py

@@ -14,11 +14,16 @@
 # ==============================================================================
 """Registry responsible for built-in keras classes."""
 
-from keras.engine import base_layer
 import tensorflow as tf
 
 from tensorflow_model_optimization.python.core.sparsity.keras import prunable_layer
 
+try:
+  from keras.engine import base_layer  # pylint: disable=g-import-not-at-top
+except ImportError:
+  # Path as seen in pip packages as of TF/Keras 2.13.
+  from keras.src.engine import base_layer  # pylint: disable=g-import-not-at-top
+
 # TODO(b/139939526): move to public API.
 
 layers = tf.keras.layers