protected void addSslClientCertChecks(ChannelPipeline pipeline) {
        if (channelConfig.get(ZuulDependencyKeys.SSL_CLIENT_CERT_CHECK_REQUIRED)) {
            if (this.sslClientCertCheckChannelHandler == null) {
                throw new IllegalArgumentException("A sslClientCertCheckChannelHandler is required!");
            }
            pipeline.addLast(this.sslClientCertCheckChannelHandler);
        }
    }
Call {@link #BaseZuulChannelInitializer(String, ChannelConfig, ChannelConfig, ChannelGroup)} instead.
zuul-core/src/main/java/com/netflix/zuul/netty/server/BaseZuulChannelInitializer.java