private static void assertRefCnt(int start, int end, int refCnt) {
        for (int i = start; i < end; i++) {
            assertThat(byteBufs.get(i).refCnt()).isEqualTo(refCnt);
        }
    }
A test for the {@link SignalQueue} in {@link DefaultStreamMessageDuplicator}.
Queue expansion behaves differently when odd/even number head wrap-around happens.
core/src/test/java/com/linecorp/armeria/common/stream/StreamMessageDuplicatorTest.java