code: def populate_folds(self, n_folds):
      super(RawDataReader, self).populate_folds(n_folds)
      for s in self.samples():
          s["meta"].fold_id = s["fold_id"]
  
file_path: calamari/calamari_ocr/ocr/dataset/datareader/raw.py
imports: from typing import Generator
  from tfaip.data.pipeline.definitions import PipelineMode
  from calamari_ocr.ocr.dataset.params import SampleMeta, InputSample
  from calamari_ocr.ocr.dataset.datareader.base import CalamariDataGenerator
label_desc: Use image node_id 2 for calling the RawDataReader obj's underlying member method code with example usage: obj.populate_folds(n_folds) without return types