rem: return $H(hash).inject($H(this), function(mergedHash, pair) { mergedHash[pair.key] = pair.value; return mergedHash; 
add: return this.select(function(value) { return !values.include(value); 
context:     return $H(hash).inject($H(this), function(mergedHash, pair) {      mergedHash[pair.key] = pair.value;      return mergedHash;    });
meta: 2320	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/2320/19200c26046dc00f15305e03b7c1d28b4c38c952/prototype.js/clean/web/scripts/prototype.js