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)


constructor(attributes) {
    super(TEMPLATE_NS_ID, "encryptionMethods",  true);
    this.id = attributes.id || "";
    this.type = getStringOption(attributes.type, ["optional", "required"]);
    this.use = attributes.use || "";
    this.usehref = attributes.usehref || "";
    this.encryptionMethod = new XFAObjectArray();
  }
}
class Event extends XFAObject {
  constructor(attributes) {
    super(TEMPLATE_NS_ID, "event",  true);
    this.activity = getStringOption(attributes.activity, [
      "click",
      "change",
      "docClose",
      "docReady",
      "enter",
      "exit",
      "full",
      "indexChange",
      "initialize",
      "mouseDown",
      "mouseEnter",
      "mouseExit",
      "mouseUp",
      "postExecute",
      "postOpen",
      "postPrint",
      "postSave",