Ssl setClientAuth(ClientAuth clientAuth) {
            this.clientAuth = clientAuth;
            return this;
        }
Sets whether the client authentication is not none ({@link ClientAuth#NONE}), optional
({@link ClientAuth#OPTIONAL}) or required ({@link ClientAuth#REQUIRE}).
dropwizard2/src/main/java/com/linecorp/armeria/dropwizard/ArmeriaSettings.java