code: def get_ext_data(self):
      ext_data_num = 0
      for op in self.ops:
          if hasattr(op, "ext_data_num"):
              ext_data_num = getattr(op, "ext_data_num")
              break
      load_data_ops = self.ops[: self.ext_op_transform_idx]
      ext_data = []
  
      while len(ext_data) < ext_data_num:
          file_idx = self.data_idx_order_list[
              np.random.randint(self.__len__())
          ]
          data_line = self.data_lines[file_idx]
          data_line = data_line.decode("utf-8")
          substr = data_line.strip("\n").split(self.delimiter)
          file_name = substr[0]
          file_name = self._try_parse_filename_list(file_name)
          label = substr[1]
          img_path = os.path.join(self.data_dir, file_name)
          data = {"img_path": img_path, "label": label}
          if not os.path.exists(img_path):
              continue
          with open(data["img_path"], "rb") as f:
              img = f.read()
              data["image"] = img
          data = transform(data, load_data_ops)
  
          if data is None:
              continue
          if "polys" in data.keys():
              if data["polys"].shape[1] != 4:
                  continue
          ext_data.append(data)
      return ext_data
  
imports: import numpy
  import cv2
  import math
  import os
  import json
  import random
  import traceback
  from paddle.io import Dataset
  from .imaug import transform, create_operators
label_desc: Use image node_id 6 for calling the SimpleDataSet obj's underlying member method code with example usage: obj.get_ext_data() and returns: ext_data