rem: return this.select(function(value) { return !values.include(value); }); 
add: return this.collect(function(value, index) { return {value: value, criteria: iterator(value, index)}; }).sort(function(left, right) { 
context:     return this.select(function(value) {      return !values.include(value);    });
meta: 2801	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/2801/7e143d2df37946a5416f0f043869478087652eb6/prototype.js/clean/examples/testcases/prototype.js