code: def _sample1(self):
      self.rbuf.sample(1)
  
imports: import collections
  import copy
  import os
  import tempfile
  import unittest
  import numpy
  import pytest
  import torch
  from pfrl import replay_buffer, replay_buffers
label_desc: Use image node_id 2 for calling the TestReplayBufferFail obj's underlying member method code with example usage: obj._sample1() without return types