code: def size(self, index):
      return self.item_size
  
file_path: fairseq/fairseq/benchmark/dummy_dataset.py
imports: import numpy
  from fairseq.data import FairseqDataset
label_desc: Use image node_id 7 for calling the DummyDataset obj's underlying member method code with example usage: obj.size(index) and returns: self