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)


}
    if (!ui.attributes.class) {
      ui.attributes.class = [];
    }
    switch (this.caption.placement) {
      case "left":
        ui.children.splice(0, 0, caption);
        ui.attributes.class.push("xfaLeft");
        break;
      case "right":
        ui.children.push(caption);
        ui.attributes.class.push("xfaLeft");
        break;
      case "top":
        ui.children.splice(0, 0, caption);
        ui.attributes.class.push("xfaTop");
        break;
      case "bottom":
        ui.children.push(caption);
        ui.attributes.class.push("xfaTop");
        break;
      case "inline":
        
        ui.attributes.class.push("xfaLeft");
        break;
    }
    return HTMLResult.success(createWrapper(this, html), bbox);
  }
}
class Fill extends XFAObject {