code: def _get_file_iterator(self, file_obj):
          
          file_obj.seek(0)
  
          return iter(lambda: file_obj.read(self.read_bs), '')
docs: For given `file_obj` return iterator, which will read the file in
          `self.read_bs` chunks.
  
          Args:
              file_obj (file): File-like object.
  
          Return:
              iterator: Iterator reading the file-like object in chunks.