@Override
    public int hashCode() {
        int result = from;
        result = 31 * result + to;
        return result;
    }
@Test
    void testHashCode() {
        RangeSet rangeSet1 = new RangeSet(5, 10);
        RangeSet rangeSet2 = new RangeSet(5, 10);
        RangeSet rangeSet3 = new RangeSet(6, 10);

        assertEquals(rangeSet1.hashCode(), rangeSet2.hashCode());
        assertNotEquals(rangeSet1.hashCode(), rangeSet3.hashCode());
    }