def METHOD_NAME(self):
    mel_basis = np_transforms.build_mel_basis(**self.config)
    mel = np.random.rand(self.config.num_mels, 20)  # [C, T]
    spec = np_transforms.METHOD_NAME(mel=mel, mel_basis=mel_basis)
    self.assertEqual(spec.shape, (self.config.fft_size // 2 + 1, 20))