@Test
void getSortedSet()
{

    SortedSet<Double> result = this.tool.getSortedSet();
    assertNotNull(result, "Returned null instead of a set");
    assertTrue(result.isEmpty(), "Returned set wasn't initially empty");
    // Check that the set is indeed sorted
    Random r = new Random();
    for (int i = 0; i < 100; ++i) {
        result.add(r.nextDouble());
    }
    Double d = 0.0;
    for (Double e : result) {
        assertTrue(e >= d, "Set doesn't preserve the natural order of the elements");
        d = e;
    }
}