Attach (recommended) or Link to PDF file here:  [test.pdf](https://akmer.aikucun.com/a94a8fe5ccb19ba61c4c0873d391e987982fbbd3_1616477914120_83.pdf)


Configuration:
- Web browser and its version: chrome 87.0.4280.88
- Operating system and its version: windows10
- PDF.js version: 2.6.347
- Is a browser extension:

Steps to reproduce the problem:
1. just open 

What is the expected behavior? (add screenshot)

What went wrong? (add screenshot)
![image](https://user-images.githubusercontent.com/17724610/112087066-473f8f80-8bc8-11eb-8efb-56139ec42a9c.png)

Link to a viewer (if hosted on a site other than mozilla.github.io/pdf.js or as Firefox/Chrome extension):

}
      const entries = obj.get(this._type);
      if (Array.isArray(entries)) {
        for (let i = 0, ii = entries.length; i < ii; i += 2) {
          dict[xref.fetchIfRef(entries[i])] = xref.fetchIfRef(entries[i + 1]);
        }
      }
    }
    return dict;
  }
  get(key) {
    if (!this.root) {
      return null;
    }
    const xref = this.xref;
    let kidsOrEntries = xref.fetchIfRef(this.root);
    let loopCount = 0;
    const MAX_LEVELS = 10;
    
    
    while (kidsOrEntries.has("Kids")) {
      if (++loopCount > MAX_LEVELS) {
        warn(`Search depth limit reached for "${this._type}" tree.`);
        return null;
      }
      const kids = kidsOrEntries.get("Kids");
      if (!Array.isArray(kids)) {
        return null;
      }
      let l = 0,