---
root:
  items:
    - type: stacking-context
      bounds: [0, 0, 100, 100]
      filters:
        - svgfe: SourceGraphic
        - svgfe: SourceAlpha
        - svgfe: opacity
          linear: false
          subregion: [0, 0, 100, 100]
          in: 0
          value: 0.5
      items:
        - type: rect
          bounds: [0, 0, 100, 100]
          color: [128, 0, 0, 1]
