rem: return '#<Hash:{' + this.map(function(pair) { return pair.map(Object.inspect).join(': '); }).join(', ') + '}>'; 
add: return this.select(function(value) { return !values.include(value); }); 
context:     return '#<Hash:{' + this.map(function(pair) {      return pair.map(Object.inspect).join(': ');    }).join(', ') + '}>';
meta: 9100	/local1/tlutelli/issta_data/temp/all_js/javascript/2007_temp/2007/9100/2d4247a14ff4ce25ad80cbc65b787dfde7ddb16e/prototype.js/buggy/typo3/contrib/prototype/prototype.js