code: def testEmptyBuffer(self, rb_cls):
      self._create_replay_buffer(rb_cls=rb_cls)
      ds = self._replay_buffer.as_dataset()
      if tf.executing_eagerly():
          next(iter(ds))
      else:
          get_next = tf.compat.v1.data.make_one_shot_iterator(
              ds
          ).get_next()
          self.evaluate(get_next)
  
imports: from __future__ import division
  from __future__ import unicode_literals
  import os
  from absl.testing import parameterized
  import numpy
  import tensorflow
  from tf_agents.replay_buffers import py_hashed_replay_buffer
  from tf_agents.replay_buffers import py_uniform_replay_buffer
  from tf_agents.specs import array_spec
  from tf_agents.trajectories import policy_step
  from tf_agents.trajectories import time_step
  from tf_agents.trajectories import trajectory
  from tf_agents.utils import nest_utils
label_desc: Use image node_id 4 for calling the PyUniformReplayBufferTest obj's underlying member method code with example usage: obj.testEmptyBuffer(rb_cls) without return types