Dynamic DOM prototype

gistfile1.js

var originalNodeListProto = NodeList.prototype;
var temporaryNodeListProto = Object.create(NodeList.prototype);
temporaryNodeListProto.a = 1;

NodeList.prototype = temporaryNodeListProto;

var l = document.querySelectorAll('a');
console.log(l.a); // inherited from which prototype?

NodeList.prototype = originalNodeListProto;
console.log(l.a); // checking if the result is the same than above :-)