Attach (recommended) or Link to PDF file here:
https://www.canada.ca/content/dam/ircc/migration/ircc/english/pdf/kits/forms/eimm5669e.pdf
[eimm5669e.pdf](https://github.com/mozilla/pdf.js/files/7225677/eimm5669e.2.pdf)

Configuration:
- Web browser and its version: Firefox nightly
- Operating system and its version: Linux Debian

Steps to reproduce the problem:
1. Look at the bottom of page 2

yield* getContainedChildren(this);
  }
  [$getSubformParent]() {
    let parent = this[$getParent]();
    while (!(parent instanceof Subform)) {
      parent = parent[$getParent]();
    }
    return parent;
  }
  [$isBindable]() {
    return true;
  }
}
class SubjectDN extends ContentObject {