SubElements := Rectangle {

    Rectangle {
        color: yellow;
    }

    color: blue;

    Rectangle {
        color: red;
    }

    foo := Rectangle {}
    parent := Rectangle {}
//  ^error{'parent' is a reserved id}
    root := Rectangle {
//  ^error{'root' is a reserved id}
        self := Rectangle {}
//      ^error{'self' is a reserved id}
    }



}