code: def test_draw_border_map(self):
      img_size = (40, 40)
      thr_map = np.zeros(img_size, dtype=np.float32)
      thr_mask = np.zeros(img_size, dtype=np.float32)
      polygon = np.array(
          [20, 21, -14, 20, -11, 30, -22, 26], dtype=np.float32
      )
      self.db_loss._draw_border_map(polygon, thr_map, thr_mask)
  
file_path: mmocr/tests/test_models/test_textdet/test_module_losses/test_db_module_loss.py
imports: from unittest import TestCase
  import numpy
  import torch
  from mmengine.structures import InstanceData
  from mmocr.models.textdet.module_losses import DBModuleLoss
  from mmocr.structures import TextDetDataSample
label_desc: Use image node_id 3 for calling the TestDBModuleLoss obj's underlying member method code with example usage: obj.test_draw_border_map() without return types