Attach (recommended) or Link to PDF file here:
issue13500 (in test corpus)

This regressed when landing #13566. 

What is the expected behavior? (add screenshot)
<img width="664" alt="image" src="https://user-images.githubusercontent.com/942640/122467522-7bc8aa80-cf6f-11eb-9d4d-311eb7c64fb2.png">


What went wrong? (add screenshot)
![image](https://user-images.githubusercontent.com/942640/122467565-85eaa900-cf6f-11eb-9c10-8a8686ed440c.png)


yield* getContainedChildren(this);
  }
  [$isTransparent]() {
    return true;
  }
  [$addHTML](html, bbox) {
    const [x, y, w, h] = bbox;
    this[$extra].width = Math.max(this[$extra].width, x + w);
    this[$extra].height = Math.max(this[$extra].height, y + h);
    this[$extra].children.push(html);
  }
  [$getAvailableSpace]() {