@Override
    public Range<T> firstRange() {
        return rangeSet.firstRange();
    }
@Test
    public void testFirstRange() {
        set = new RangeSetWrapper<>(consumer, reverseConvert, managedCursor);
        assertNull(set.firstRange());
        set.addOpenClosed(0, 97, 0, 99);
        assertEquals(set.firstRange(), Range.openClosed(new LongPair(0, 97), new LongPair(0, 99)));
        assertEquals(set.size(), 1);
        set.addOpenClosed(0, 98, 0, 105);
        assertEquals(set.firstRange(), Range.openClosed(new LongPair(0, 97), new LongPair(0, 105)));
        assertEquals(set.size(), 1);
        set.addOpenClosed(0, 5, 0, 75);
        assertEquals(set.firstRange(), Range.openClosed(new LongPair(0, 5), new LongPair(0, 75)));
        assertEquals(set.size(), 2);
    }