public final void removeInboundHandler() {
        checkAdded();
        inboundCtx.remove();
    }
@Test
    public void testInboundRemoveBeforeAdded() {
        final CombinedChannelDuplexHandler<ChannelInboundHandler, ChannelOutboundHandler> handler =
                new CombinedChannelDuplexHandler<ChannelInboundHandler, ChannelOutboundHandler>(
                        new ChannelInboundHandlerAdapter(), new ChannelOutboundHandlerAdapter());
        assertThrows(IllegalStateException.class, new Executable() {
            @Override
            public void execute() {
                handler.removeInboundHandler();
            }
        });
    }