code: def __init__(self):
      super().__init__()
      self.dataset_name = "masked_vqa2"
      self.dataset_class = MaskedVQA2Dataset
  
imports: from mmf.common.registry import registry
  from mmf.datasets.builders.vqa2.builder import VQA2Builder
  from mmf.datasets.builders.vqa2.masked_dataset import MaskedVQA2Dataset
label_desc: Use image node_id 1 to create a new MaskedVQA2Builder object from inherited base classes: VQA2Builder with example: obj = MaskedVQA2Builder()