code: def testAllModelCheckpointPaths(self):
      save_dir = self._get_test_dir("all_models_test")
      abs_path = os.path.join(save_dir, "model-0")
      for paths in [None, [], ["model-2"]]:
          ckpt = checkpoint_management.generate_checkpoint_state_proto(
              save_dir, abs_path, all_model_checkpoint_paths=paths
          )
          self.assertEqual(ckpt.model_checkpoint_path, abs_path)
          self.assertTrue(os.path.isabs(ckpt.model_checkpoint_path))
          self.assertEqual(
              len(ckpt.all_model_checkpoint_paths),
              len(paths) if paths else 1,
          )
          self.assertEqual(
              ckpt.all_model_checkpoint_paths[-1], abs_path
          )
  
imports: import contextlib
  import os
  import pathlib
  import shutil
  import tempfile
  from google.protobuf import text_format
  from tensorflow.core.protobuf import saver_pb2
  from tensorflow.python.checkpoint import checkpoint
  from tensorflow.python.checkpoint import checkpoint_management
  from tensorflow.python.eager import context
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import ops
  from tensorflow.python.framework import test_util
  from tensorflow.python.lib.io import file_io
  from tensorflow.python.ops import variables
  from tensorflow.python.platform import gfile
  from tensorflow.python.platform import test
  from tensorflow.python.platform import tf_logging
  from tensorflow.python.training import saver
  from tensorflow.python.training.checkpoint_state_pb2 import CheckpointState
label_desc: Use image node_id 4 for calling the CheckpointStateTest obj's underlying member method code with example usage: obj.testAllModelCheckpointPaths() without return types