def METHOD_NAME(self):
    # GUI tests for bandpass filter are in test_spectrogram.py
    sig1 = np.sin(2 * np.pi * 0.2 * np.arange(0, 100))
    sig2 = np.sin(2 * np.pi * 0.3 * np.arange(0, 100))
    sig = sig1 + sig2
    filtered1 = Filter.apply_bandpass_filter(sig, 0.1, 0.2)
    filtered2 = Filter.apply_bandpass_filter(sig, 0.2, 0.1)
    self.assertTrue(np.array_equal(filtered1, filtered2))