@Test
public void testLabels() {

    double[][] mtx =
        new double[][] {
            {1.0, 1.0},
            {1.0, 2.0},
            {2.0, 1.0},
            {-1.0, -1.0},
            {-1.0, -2.0},
            {-2.0, -1.0}};
    double[] lbs = new double[] {1.0, 1.0, 1.0, 2.0, 2.0, 2.0};
    LabeledVectorSet dataset = new LabeledVectorSet(mtx, lbs);
    final double[] labels = dataset.labels();
    for (int i = 0; i < lbs.length; i++)
        assertEquals(lbs[i], labels[i], 0);
}