return Object.extend(destination, source); 
return Object.extend(destination.prototype, source); 
  mixin: function(destination, source) {    return Object.extend(destination, source);  }
5582	/local1/tlutelli/issta_data/temp/all_js/javascript/2007_temp/2007/5582/bfba40e0cda57a214a79fcce3acfa8a8d2bbeeb0/base.js/buggy/src/base.js