root:
  items:
    - type: scroll-frame
      bounds: [0, 0, 500, 500]
      content-size: [1000, 1000]
      scroll-offset: [0, 300]
      items:
      - type: scroll-frame
        bounds: [0, 300, 50, 50]
        items:
        - type: scroll-frame
          bounds: [0, 300, 50, 50]
          items:
            - type: rect
              bounds: [0, 300, 50, 50]
              color: green