see more from https://github.com/openzipkin/brave/issues/867, also see https://github.com/apache/incubator-dubbo/issues/3576
: NetUtils.filterLocalHost(remoteAddress.getAddress().getHostAddress());
    }
    /**
     * get remote port.
     *
     * @return remote port
     */
    public int getRemotePort() {
        return remoteAddress == null ? 0 : remoteAddress.getPort();
    }
    /**
     * get attachment.
     *
     * @param key
     * @return attachment
     */
    public String getAttachment(String key) {
        return attachments.get(key);
    }
    /**
     * set attachment.
     *
     * @param key
     * @param value
     * @return context
     */
    public RpcContext setAttachment(String key, String value) {
        if (value == null) {
            attachments.remove(key);
        } else {