def METHOD_NAME(series_data):
    """Ensure warning is raised by unequal sampling frequencies"""
    firstarr, secondarr, seglen = series_data
    f_s = 0.001
    first = TimeSeries(firstarr, sample_rate=f_s)
    second = TimeSeries(secondarr, sample_rate=f_s * 2.32)
    with pytest.warns(UserWarning, match="Sampling frequencies are unequal"):
        spectral.coherence(first, second, segmentlength=seglen)
    with pytest.raises(ValueError):
        spectral.coherence(first, second, segmentlength=seglen,
                           downsample=False)
    coh1 = spectral.coherence(first, second, segmentlength=seglen)
    coh2 = spectral.coherence(first, second, segmentlength=seglen,
                              downsample=True)
    assert all(np.array(coh1.data) == np.array(coh2.data))