// Rhino $ js -f library.js -f solution-2-d.js -

var fields = {};

fields.__init__ = function(keys){
    this.keys = keys;
};

fields.copy_attributes = function(src, tgt){

    var keys = this.keys;
    var key;
    var i;

    for(i=0; i< keys.length; i++){
        key = keys[i];
        tgt[key] = src['get_' + key]();
    };
};

var Fields = SimpleClass(fields);