code: def testGatherAllEmpty(self):
      spec = specs.TensorSpec([], tf.int32, "action")
      replay_buffer = episodic_replay_buffer.EpisodicReplayBuffer(spec)
  
      items = replay_buffer.gather_all()
      expected = []
  
      self.evaluate(tf.compat.v1.global_variables_initializer())
      self.evaluate(tf.compat.v1.local_variables_initializer())
      items_ = self.evaluate(items)
      self.assertAllClose(expected, items_)
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from absl.testing import parameterized
  import numpy
  import tensorflow
  from tf_agents import specs
  from tf_agents.replay_buffers import episodic_replay_buffer
  from tf_agents.utils import common
  from tf_agents.utils import test_utils
  from tensorflow.python.ops import list_ops
label_desc: Use image node_id 24 for calling the EpisodicReplayBufferTest obj's underlying member method code with example usage: obj.testGatherAllEmpty() without return types