@Test
public void toSummary() {

    DenseVectorSummary summary = (DenseVectorSummary) summarizer().toSummary();
    assertEquals(5, summary.count);
    assertArrayEquals(new double[]{15.0, -15.0, 15.0}, summary.sum.getData(), 10e-6);
    assertArrayEquals(new double[]{55.0, 55.0, 45.0}, summary.squareSum.getData(), 10e-6);
    assertArrayEquals(new double[]{1.0, -5.0, 3.0}, summary.min.getData(), 10e-6);
    assertArrayEquals(new double[]{5.0, -1.0, 3.0}, summary.max.getData(), 10e-6);
    assertArrayEquals(new double[]{15.0, 15.0, 15.0}, summary.normL1.getData(), 10e-6);
}