code: def _get_mock_spec(self):
      spec = [
          specs.TensorSpec([3], tf.float32, "action"),
          [
              specs.TensorSpec([5], tf.float32, "lidar"),
              specs.TensorSpec([3, 2], tf.float32, "camera"),
          ],
      ]
      return spec
  
file_path: agents/tf_agents/train/utils/replay_buffer_utils_test.py
imports: import tensorflow
  from tf_agents import specs
  from tf_agents.replay_buffers import reverb_replay_buffer
  from tf_agents.replay_buffers import reverb_utils
  from tf_agents.train.utils import replay_buffer_utils
  from tf_agents.utils import lazy_loader
  from tf_agents.utils import test_utils
label_desc: Use image node_id 1 for calling the ReplayBufferUtilsTest obj's underlying member method code with example usage: obj._get_mock_spec() and returns: spec