code: def sample(self):
      samples_dict = {"observations": [], "rewards": []}
      for i in range(self._sample_count):
          samples_dict["observations"].append(
              self.obs_filter(np.random.randn())
          )
          samples_dict["rewards"].append(
              self.rew_filter(np.random.randn())
          )
      return SampleBatch(samples_dict)
  
file_path: ray/python/ray/rllib/tests/mock_worker.py
imports: import numpy
  import ray
  from ray.rllib.evaluation.worker_set import WorkerSet
  from ray.rllib.policy.sample_batch import SampleBatch
  from ray.rllib.utils.filter import MeanStdFilter
label_desc: Use image node_id 2 for calling the _MockWorker obj's underlying member method code with example usage: obj.sample() and returns: SampleBatch