code: def test_for_json_encodes_object_nested_in_list_within_dict(self):
      self.assertRoundTrip(
          {"list": [0, ForJson(), 2, 3]},
          {"list": [0, ForJson().for_json(), 2, 3]},
      )
  
imports: import unittest
  import simplejson
label_desc: Use image node_id 4 for calling the TestForJson obj's underlying member method code with example usage: obj.test_for_json_encodes_object_nested_in_list_within_dict() without return types