rem: return false; 
add: return null; 
context: function  testSimpleEnum(sHistory)// testSimpleEnum() returns an enumerated list of all the session history// entries. It accepts the session history object as the input parameter{  if (!sHistory) {    alert("Didn't get SessionHistory object");    return false;    }   var simpleEnum = sHistory.SHistoryEnumerator;      return simpleEnum;}
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/e0e3a32c7d2e7f0e0d5fed54932a27821b36aa27/nsISHistoryTestLib.js/buggy/embedding/qa/jstests/sHistory/nsISHistoryTestLib.js