NS_PRECONDITION(sXPCNativeWrapperClass, "Must know what the XPCNativeWrapper class is!"); return ::JS_GetClass(cx, obj) == sXPCNativeWrapperClass;
  static PRBool ObjectIsNativeWrapper(JSContext* cx, JSObject* obj)  {    NS_PRECONDITION(sXPCNativeWrapperClass,                    "Must know what the XPCNativeWrapper class is!");    return ::JS_GetClass(cx, obj) == sXPCNativeWrapperClass;  }