rem: rv += rv ? ", " + p : p; 
add: rv.push(p); 
context: function keys (o){    var rv = "";        for (var p in o)        rv += rv ? ", " + p : p;    return rv;    }
meta: 1622	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/1622/bee12c37567fda66edb1bcb13eb1a88281bcaed1/utils.js/buggy/js/lib/utils.js