code: def test_init(self):
      with self.assertRaises(AssertionError):
          SDMGRPostProcessor(link_type=1)
  
      with self.assertRaises(AssertionError):
          SDMGRPostProcessor(link_type="one-to-one")
  
file_path: mmocr/tests/test_models/test_kie/test_postprocessors/test_sdmgr_postprocessor.py
imports: import copy
  from unittest import TestCase
  import torch
  from mmengine.structures import InstanceData
  from mmocr.models.kie.postprocessors import SDMGRPostProcessor
  from mmocr.structures import KIEDataSample
label_desc: Use image node_id 3 for calling the TestSDMGRPostProcessor obj's underlying member method code with example usage: obj.test_init() without return types