@Override
    public ByteBuf ensureWritable(int minWritableBytes) {
        ensureWritable0(checkPositiveOrZero(minWritableBytes, "minWritableBytes"));
        return this;
    }
@Test
    public void testEnsureWritableAfterRelease() {
        assertThrows(IllegalReferenceCountException.class, new Executable() {
            @Override
            public void execute() {
                releasedBuffer().ensureWritable(16);
            }
        });
    }