@Override
    public byte readByte() {
        checkReadableBytes0(1);
        int i = readerIndex;
        byte b = _getByte(i);
        readerIndex = i + 1;
        return b;
    }
@Test
    public void testReadByteAfterRelease() {
        assertThrows(IllegalReferenceCountException.class, new Executable() {
            @Override
            public void execute() {
                releasedBuffer().readByte();
            }
        });
    }