code: def test_missing_group_id(self):
      sampler = SequentialSampler(list(range(100)))
      group_ids = [1] * 100
      samples = GroupedBatchSampler(sampler, group_ids, 2)
  
      for mini_batch in samples:
          self.assertEqual(len(mini_batch), 2)
  
imports: import itertools
  import math
  import operator
  import unittest
  import torch
  from torch.utils import data
  from torch.utils.data.sampler import SequentialSampler
  from detectron2.data.build import worker_init_reset_seed
  from detectron2.data.common import DatasetFromList, ToIterableDataset
  from detectron2.data.samplers import GroupedBatchSampler, InferenceSampler, RepeatFactorTrainingSampler, TrainingSampler
  from detectron2.utils.env import seed_all_rng
label_desc: Use image node_id 1 for calling the TestGroupedBatchSampler obj's underlying member method code with example usage: obj.test_missing_group_id() without return types