code: def _check_unk(self, sample_info):
      if not self._no_unk:
          return False
      else:
          index = self.answer_processor.word2idx(
              sample_info["answers"][0]
          )
          return index == self.answer_processor.answer_vocab.UNK_INDEX
  
file_path: mmf/mmf/datasets/builders/visual_genome/dataset.py
imports: import copy
  import json
  import torch
  from mmf.common.sample import Sample, SampleList
  from mmf.datasets.builders.vqa2 import VQA2Dataset
  from mmf.datasets.databases.scene_graph_database import SceneGraphDatabase
label_desc: Use image node_id 6 for calling the VisualGenomeDataset obj's underlying member method code with example usage: obj._check_unk(sample_info) and returns: False, unknown