rem: return destination; 
add:  element._extended = true; return element; 
context: Object.extend = function(destination, source) {  for (property in source) {    destination[property] = source[property];  }  return destination;}
meta: 2801	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/2801/7e143d2df37946a5416f0f043869478087652eb6/prototype.js/clean/examples/testcases/prototype.js