code: def _build_dataloaders(self):
      dataloaders = {}
      for idx in range(self.NUM_DATALOADERS):
          dataloaders[f"numbers_{idx}"] = torch.utils.data.DataLoader(
              dataset=NumbersDataset((idx + 1) * (10**idx)),
              num_workers=0,
          )
      return dataloaders
  
file_path: mmf/tests/datasets/test_iteration_strategies.py
imports: import unittest
  from collections import Counter
  import numpy
  import torch
  from mmf.datasets import iteration_strategies
  from tests.test_utils import NumbersDataset
label_desc: Use image node_id 2 for calling the TestIterationStrategies obj's underlying member method code with example usage: obj._build_dataloaders() and returns: dataloaders