code: def test_label_encoder_decode_to_same_string():
      encoder = encoders.LabelEncoder(["a", "b"])
  
      result = encoder.postprocess([[0], [1]])
  
      assert np.array_equal(result, np.array([["a"], ["b"]]))
  
file_path: autokeras/autokeras/preprocessors/encoders_test.py
imports: import numpy
  import tensorflow
  from autokeras import preprocessors
  from autokeras.preprocessors import encoders
  from autokeras.utils import data_utils
label_desc: Use image node_id 3 for calling a global function with example usage: test_label_encoder_decode_to_same_string() without return types