see more from https://github.com/openzipkin/brave/issues/867, also see https://github.com/apache/incubator-dubbo/issues/3576
}
    /**
     * remove value.
     *
     * @param key
     * @return value
     */
    public RpcContext remove(String key) {
        values.remove(key);
        return this;
    }
    /**
     * get value.
     *
     * @param key
     * @return value
     */
    public Object get(String key) {
        return values.get(key);
    }
    /**
     * @deprecated Replace to isProviderSide()
     */
    @Deprecated
    public boolean isServerSide() {
        return isProviderSide();
    }
    /**
     * @deprecated Replace to isConsumerSide()
     */