code: def testReturnsNoneAfterTimeout(self):
      start = time.time()
      ret = checkpoint_utils.wait_for_new_checkpoint(
          "/non-existent-dir", "foo", timeout=1.0, seconds_to_sleep=0.5
      )
      end = time.time()
      self.assertIsNone(ret)
  
      # We've waited one second.
      self.assertGreater(end, start + 0.5)
  
      # The timeout kicked in.
      self.assertLess(end, start + 1.1)
  
imports: import os
  import pathlib
  import time
  import numpy
  from tensorflow.core.protobuf import config_pb2
  from tensorflow.python.checkpoint import checkpoint
  from tensorflow.python.client import session
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import errors_impl
  from tensorflow.python.framework import ops
  from tensorflow.python.framework import test_util
  from tensorflow.python.ops import init_ops
  from tensorflow.python.ops import partitioned_variables
  from tensorflow.python.ops import resource_variable_ops
  from tensorflow.python.ops import variable_scope
  from tensorflow.python.ops import variables
  from tensorflow.python.platform import gfile
  from tensorflow.python.platform import test
  from tensorflow.python.training import checkpoint_utils
  from tensorflow.python.training import saver
label_desc: Use image node_id 1 for calling the WaitForNewCheckpointTest obj's underlying member method code with example usage: obj.testReturnsNoneAfterTimeout() without return types