code: def test_encode_decode_enum(self):
      class Enum(enum.Enum):
          CLASS_A = "a"
          CLASS_B = "b"
  
      config = {"key": Enum.CLASS_A, "key2": Enum.CLASS_B}
      string = json_utils.Encoder().encode(config)
      loaded = json_utils.decode(string)
      self.assertAllEqual({"key": "a", "key2": "b"}, loaded)
  
file_path: keras/keras/legacy/saving/json_utils_test.py
imports: import enum
  import pytest
  from keras import backend
  from keras import testing
  from keras.legacy.saving import json_utils
label_desc: Use image node_id 2 for calling the JsonUtilsTestAllBackends obj's underlying member method code with example usage: obj.test_encode_decode_enum() without return types