Method bug15

src/test/java/pascal/taie/util/collection/IBitSetTest.java:451–459

()

    }

    @Test
    void bug15() {
        set.set(1);
        set.set(64);
        assertEquals(63, set.previousClearBit(64));
        set.clear(0);
        set.set(1);
        assertEquals(63, set.previousClearBit(64));
    }

    @Test
    void randomMultiEntry() {