code: def reader(self):
      if self._reader is None:
          self._reader = self.generator_params.create(self.mode)
  
      return self._reader
  
file_path: calamari/calamari_ocr/ocr/dataset/pipeline.py
imports: from typing import Iterable
  from tfaip.data.pipeline.datapipeline import DataPipeline, DataGenerator
  from tfaip.data.pipeline.definitions import Sample, PipelineMode
  from calamari_ocr.ocr.dataset.datareader.base import CalamariDataGeneratorParams
label_desc: Use image node_id 2 for calling the CalamariPipeline obj's underlying member method code with example usage: obj.reader() and returns: self