@Test
public void testUpdateLabel() {

    Vector vec = distance.prepareVectorData(Tuple2.of(denseVector1, null)).getVector();
    Assert.assertEquals(vec.normL2(), 1.0, 0.01);
    FastDistanceMatrixData matrixData = initMatrixData();
    DenseMatrix matrix = matrixData.getVectors();
    for (int i = 0; i < matrix.numCols(); i++) {
        double[] data = matrix.getColumn(i);
        Assert.assertEquals(Math.sqrt(BLAS.dot(data, data)), 1.0, 0.01);
    }
}