public Builder setSSLContext(final SSLContext ctx) {
            if (ctx == null) {
                throw(new IllegalArgumentException(
                        "SSL context cannot be null"));
            }
            if (config.sslConnector != null) {
                throw(new IllegalArgumentException("SSLConnector and SSLContext can not both be set"));
            }
            config.sslContext = ctx;
            return this;
        }