@Test
public void nonZeroes() {

    assertNotNull(MathTestConstants.NULL_VAL, testVector.nonZeroes());
    double[] data = initVector();
    assertNotNull(MathTestConstants.NULL_VAL, testVector.nonZeroes());
    Assert.assertEquals(MathTestConstants.VAL_NOT_EQUALS, StreamSupport.stream(testVector.nonZeroes().spliterator(), false).count(), Arrays.stream(data).filter(x -> x != 0d).count());
    addNilValues(data);
    Assert.assertEquals(MathTestConstants.VAL_NOT_EQUALS, StreamSupport.stream(testVector.nonZeroes().spliterator(), false).count(), Arrays.stream(data).filter(x -> x != 0d).count());
}