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)


_setValue(this, value);
  }
  [$toHTML](availableSpace) {
    
    if (!this.value) {
      return HTMLResult.EMPTY;
    }
    const value = this.value[$toHTML](availableSpace).html;
    if (!value) {
      return HTMLResult.EMPTY;
    }
    const children = [];
    if (typeof value === "string") {
      children.push({
        name: "#text",
        value,
      });
    } else {
      children.push(value);
    }