see more from https://github.com/openzipkin/brave/issues/867, also see https://github.com/apache/incubator-dubbo/issues/3576
*/
    public Class<?>[] getParameterTypes() {
        return parameterTypes;
    }
    public void setParameterTypes(Class<?>[] parameterTypes) {
        this.parameterTypes = parameterTypes;
    }
    /**
     * get arguments.
     *
     * @return arguments.
     */
    public Object[] getArguments() {
        return arguments;
    }
    public void setArguments(Object[] arguments) {
        this.arguments = arguments;
    }
    /**
     * set local address.
     *
     * @param host
     * @param port
     * @return context
     */
    public RpcContext setLocalAddress(String host, int port) {
        if (port < 0) {
            port = 0;
        }
        this.localAddress = InetSocketAddress.createUnresolved(host, port);