TestCase1 1 true TestCase2 - preventExtensions & add a property x,y false TestCase3 - preventExtensions & delete a property undefined false TestCase4 - preventExtensions & modify a property x,y false 40 TestCase5 - preventExtension on global object & declare a var Exception: TypeError TestCase6 - preventExtensions, delete property and set remaining properties to non configurable/writable - SimpleDictionaryTypeHandler true true TestCase7 - preventExtensions, delete property and set remaining properties to non configurable/writable - DictionaryTypeHandler true true