JSBool IsMarked() const {return 0 != (mMemberCount & XPC_NATIVE_IFACE_MARK_FLAG);}
JSBool IsMarked() const {return 0 != (mFlags & XPC_WN_SJSFLAGS_MARK_FLAG);}
    JSBool IsMarked() const                    {return 0 != (mMemberCount & XPC_NATIVE_IFACE_MARK_FLAG);}