code: def test_circular_dict(self):
      dct = {}
      dct["a"] = dct
      self.assertRaises(ValueError, json.dumps, dct)
  
file_path: catboost/contrib/python/simplejson/py3/simplejson/tests/test_check_circular.py
imports: from unittest import TestCase
  import simplejson
label_desc: Use image node_id 1 for calling the TestCheckCircular obj's underlying member method code with example usage: obj.test_circular_dict() without return types