code: def _get_dataloader(self):
      dataset = SimpleMMFDataset(
          num_examples=100,
          dataset_name="simple",
          dataset_type="val",
          config=self.config,
      )
      dataloader = torch.utils.data.DataLoader(
          dataset=dataset,
          batch_size=self.batch_size,
          shuffle=False,
          num_workers=1,
          drop_last=False,
      )
      return dataloader
  
file_path: mmf/tests/datasets/test_multi_datamodule.py
imports: import functools
  import torch
  from mmf.datasets.lightning_multi_datamodule import LightningMultiDataModule
  from mmf.datasets.mmf_dataset_builder import MMFDatasetBuilder
  from mmf.datasets.multi_datamodule import MultiDataModule
  from omegaconf import OmegaConf
  from tests.datasets.test_mmf_dataset_builder import SimpleMMFDataset
label_desc: Use image node_id 2 for calling the MultiDataModuleTestObject obj's underlying member method code with example usage: obj._get_dataloader() and returns: dataloader