@Test
public void testStretch1()
{

    double[] signal =  FFTTest.getSampleSignal(16000);
    int samplingRate = 8000;
    double rateFactor = 0.5;
    PhaseVocoder pv = new PhaseVocoder(new BufferedDoubleDataSource(signal), samplingRate, rateFactor);
    double[] result = pv.getAllData();
    int expectedLength = pv.computeOutputLength(signal.length);
    assertTrue("Expected result length: " + expectedLength +", found: "+result.length,
            result.length == expectedLength);
}