code: def test_save_load(data_format, save_format):
      src_mono, batch_src, input_shape = get_audio(
          data_format="channels_last", n_ch=1
      )
      # test Frame save/load
      save_load_compare(
          Frame(
              frame_length=128, hop_length=64, input_shape=input_shape
          ),
          batch_src,
          np.testing.assert_allclose,
          save_format,
          Frame,
      )
      # test Energy save/load
      save_load_compare(
          Energy(
              frame_length=128, hop_length=64, input_shape=input_shape
          ),
          batch_src,
          np.testing.assert_allclose,
          save_format,
          Energy,
      )
      # test mu law layers
      save_load_compare(
          MuLawEncoding(quantization_channels=128),
          batch_src,
          np.testing.assert_allclose,
          save_format,
          MuLawEncoding,
      )
      save_load_compare(
          MuLawDecoding(quantization_channels=128),
          np.arange(0, 256, 1).reshape((1, 256, 1)),
          np.testing.assert_allclose,
          save_format,
          MuLawDecoding,
      )
      # test mfcc layer
      expand_dim = (
          (0, 3)
          if data_format in (_CH_LAST_STR, _CH_DEFAULT_STR)
          else (0, 1)
      )
      save_load_compare(
          LogmelToMFCC(n_mfccs=10),
          np.expand_dims(
              librosa.power_to_db(
                  librosa.feature.melspectrogram(src_mono).T
              ),
              expand_dim,
          ),
          np.testing.assert_allclose,
          save_format,
          LogmelToMFCC,
      )
  
file_path: kapre/tests/test_signal.py
imports: import pytest
  import numpy
  import tensorflow
  import librosa
  from kapre import Frame, Energy, MuLawEncoding, MuLawDecoding, LogmelToMFCC
  from kapre.backend import _CH_FIRST_STR, _CH_LAST_STR, _CH_DEFAULT_STR
  from utils import get_audio, save_load_compare
label_desc: Use image node_id 4 for calling a global function with example usage: test_save_load(data_format, save_format) without return types