rem: function() {return new XMLHttpRequest()} 
add: return $H(hash).inject($H(this), function(mergedHash, pair) { mergedHash[pair.key] = pair.value; return mergedHash; }); 
context:       function() {return new XMLHttpRequest()}
meta: 3974	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/3974/af9adbf17404d887f31369756326b0109da7ae2b/prototype.js/buggy/root/static/js/prototype.js