@UnstableApi
    public ServerBuilder childChannelPipelineCustomizer(
            Consumer<? super ChannelPipeline> childChannelPipelineCustomizer) {
        requireNonNull(childChannelPipelineCustomizer, "childChannelPipelineCustomizer");
        this.childChannelPipelineCustomizer =
                this.childChannelPipelineCustomizer.andThen(childChannelPipelineCustomizer);
        return this;
    }
(Advanced users only) Adds the {@link Consumer} that customizes the Netty {@link ChannelPipeline}.
This customizer is run right after the initial set of {@link ChannelHandler}s are configured.
This customizer is no-op by default.

<p>Note that usage of this customizer is an advanced feature and may produce unintended side effects,
including complete breakdown. It is not recommended if you are not familiar with Armeria and Netty
internals.
core/src/main/java/com/linecorp/armeria/server/ServerBuilder.java