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, "keyUsage");
    const options = ["", "yes", "no"];
    this.crlSign = getStringOption(attributes.crlSign, options);
    this.dataEncipherment = getStringOption(
      attributes.dataEncipherment,
      options
    );
    this.decipherOnly = getStringOption(attributes.decipherOnly, options);
    this.digitalSignature = getStringOption(
      attributes.digitalSignature,
      options
    );
    this.encipherOnly = getStringOption(attributes.encipherOnly, options);
    this.id = attributes.id || "";
    this.keyAgreement = getStringOption(attributes.keyAgreement, options);
    this.keyCertSign = getStringOption(attributes.keyCertSign, options);
    this.keyEncipherment = getStringOption(attributes.keyEncipherment, options);
    this.nonRepudiation = getStringOption(attributes.nonRepudiation, options);
    this.type = getStringOption(attributes.type, ["optional", "required"]);
    this.use = attributes.use || "";
    this.usehref = attributes.usehref || "";
  }
}
class Line extends XFAObject {