rem: new_string = this; 
add: var new_string = this; 
context: String.prototype.pad_left = function(pad_length, pad_string) {    new_string = this;    for (var i = 0; new_string.length < pad_length; i++) {        new_string = pad_string + new_string;    }    return new_string;}
meta: 3560	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/3560/ae86b2857e4ffb44ef5a29248541c4db3f8ebd02/core.js/buggy/django/contrib/admin/media/js/core.js