code: def get_data_info(self, idx: int):
      dataset_idx, sample_idx = self._get_ori_dataset_idx(idx)
      return self.datasets[dataset_idx].get_data_info(sample_idx)
  
imports: import bisect
  from unittest import TestCase
  from unittest.mock import patch
  import numpy
  from torch.utils.data import ConcatDataset, Dataset
  from mmdet.datasets.samplers import GroupMultiSourceSampler, MultiSourceSampler
label_desc: Use image node_id 2 for calling the DummyConcatDataset obj's underlying member method code with example usage: obj.get_data_info(idx) and returns: self