src/org/nutz/lang/util/NutMap.java
@Override
    public NutMap pick(String... keys) {
        if (keys.length == 0)
            return new NutMap();
        NutMap re = new NutMap();
        for (String key : keys) {
            Object val = this.get(key);
            if (null != val)
                re.put(key, val);
        }
        return re;
    }
@Override
    public NutMap pick(String... keys) {
        if (keys.length == 0)
            return new NutMap();
        NutMap re = new NutMap();
        for (String key : keys) {
            Object val = this.get(key);
            if (null != val)
                re.put(key, val);
        }
        return re;
    }
从 Map 里挑选一些键生成一个新的 Map

@param keys
键
@return 新 Map