text:   function testcase() 
    {
      var o = {
        x : 1,
        y : 2
      };
      var a = Object.keys(o);
      if (Object.isExtensible(a) === true)
      {
        return true;
      }
    }
    {
      var __result1 = testcase();
      var __expect1 = true;
    }
    