code: def get_document_iterator(
      file_path: str, file_format: str
  ) -> Iterator[str]:
      if file_format == "the_pile":
          return get_the_pile_document_iterator(file_path)
      elif file_format == "raw":
          return get_raw_document_iterator(file_path)
      elif file_format == "custom":
          return get_custom_document_iterator(file_path)
      else:
          raise NotImplementedError()
  
imports: import json
  from typing import Iterator
label_desc: Use image node_id 1 for calling a global function with example usage: get_document_iterator(file_path, file_format) and returns: get_the_pile_document_iterator, get_raw_document_iterator, get_custom_document_iterator