The following code is flagged as dead (since it's *replacing* rather than updating the existing Object):
https://github.com/mozilla/pdf.js/blob/4483cba72410027acf46630ebf252ae529704476/src/core/xfa/template.js#L2336-L2339
according to the alert in https://github.com/mozilla/pdf.js/security/code-scanning/103?query=ref%3Arefs%2Fheads%2Fmaster

Looking at the surrounding code, I can see a couple of possibilities here:
 1. This is indeed just dead code, which should be removed.
 2. The code should be moved up, and placed just *above* the previous block instead.
 3. There should be other, more invasive, changes made to this code...

/cc @calixteman Which solution is correct here?
Assuming it's either option 1 or 2, I can submit a patch to fix this.
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]() {