@Test
public void testRhoSpectralIndex() {

    assertTrue(BrrOp.isValidRhoSpectralIndex(0));
    assertFalse(BrrOp.isValidRhoSpectralIndex(10));
    assertTrue(BrrOp.isValidRhoSpectralIndex(11));
    assertFalse(BrrOp.isValidRhoSpectralIndex(14));
    assertFalse(BrrOp.isValidRhoSpectralIndex(-1));
    assertFalse(BrrOp.isValidRhoSpectralIndex(15));
}