rem: throw new Error("Extend: Function/Constructor to extend from is not a function: " + f); 
add: throw new Error("Extend: Function/Constructor to extend from is not a function: " + sFunction); 
context: Function.prototype.extend = function(sFunction, tClassName){  if (typeof sFunction != "function") {    throw new Error("Extend: Function/Constructor to extend from is not a function: " + f);  };  if (typeof tClassName != "string") {    throw new Error("Extend: Missing or malformed className: " + tClassName);  };  proto = this.prototype = new sFunction;  proto.superclass = sFunction;  proto.classname = tClassName;  proto.constructor = this;  return proto;};
meta: 1005	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/1005/8acfcbe70ac2b3b1ca578bf5df853dd9b71ae75d/QxExtend.js/clean/qooxdoo/source/script/core/QxExtend.js