Add lazy_utils method and LazyValue class. This ensures compatibility…

… with T5X for future code changes.

PiperOrigin-RevId: 487328133

orbax/checkpoint/__init__.py

@@ -15,6 +15,7 @@
 """Defines exported symbols for the `orbax` packageorbax.checkpoint."""
 
 from orbax.checkpoint import lazy_array
+from orbax.checkpoint import lazy_utils
 from orbax.checkpoint import test_utils
 from orbax.checkpoint import type_handlers
 from orbax.checkpoint.abstract_checkpoint_manager import AbstractCheckpointManager

orbax/checkpoint/lazy_utils.py

@@ -0,0 +1,19 @@
+# Copyright 2022 The Orbax Authors.
+#
+# 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.
+
+"""Dummy file used to introduce LazyValue."""
+
+
+class LazyValue:
+  pass