code: def test_cws_loader(self):
      dataset_names = ["msra", "cityu", "as", "msra"]
      for dataset_name in dataset_names:
          data_bundle = CWSLoader(dataset_name=dataset_name).load(
              f"data_for_tests/io/cws_{dataset_name}"
          )
          print(data_bundle)
  
imports: import pytest
  import os
  from fastNLP.io.loader import CWSLoader
label_desc: Use image node_id 1 for calling the TestRunCWSLoader obj's underlying member method code with example usage: obj.test_cws_loader() without return types