code: def test_5(self):
      ...
  
imports: import numpy
  import pytest
  from functools import partial
  from itertools import chain
  from copy import deepcopy
  from fastNLP.core.samplers.reproducible_sampler import RandomSampler, SortedSampler, SequentialSampler
  from tests.helpers.datasets.torch_data import TorchNormalDataset
label_desc: Use image node_id 5 for calling the TestRandomSampler obj's underlying member method code with example usage: obj.test_5() without return types