@Test
void find_whenQuarticHasTwoPairsOfEqualRealRoots_thenReturnsCorrectRoots() {

    ImmutableList<Complex> roots = QuarticRootFinder.find(1, 0, -2, 0, 1);
    ImmutableList<Pair<Double, Double>> expectedRoots = ImmutableList.of(
            Pair.of(1.0, 0.0),
            Pair.of(1.0, 0.0),
            Pair.of(-1.0, 0.0),
            Pair.of(-1.0, 0.0)
    );
    assertEquals(expectedRoots, roots);
}