I'm using `quill.formatText()` to add a custom "highlight" format to my text editor. I extended a Blot like so:

```
let Inline = Quill.import('blots/inline');
class highlight extends Inline {
    static create() {
      return super.create();
    }

    static formats() {
      return true;
    }
}
highlight.blotName = 'highlight';
highlight.className = 'highlight';
highlight.tagName = 'span';
Quill.register(highlight);

```

I then call `quill.formatText(start, selectionLength, 'highlight', true);`, which wraps my selection in a `<span class="highlight">` tag. So far so good. 

The trouble is, I want each selection to be wrapped in its own `span` tag. When I make two selections to the text, one inside the other, only the outer `span` remains. 

For example, with the text `test inside text`. If I highlight the whole string in addition to just the word `inside`, I'd expect to get:

`<span class="highlight">Test <span class="highlight">inside</span> text</span>`

Whereas I actually get:

`<span class="highlight">Test inside text</span>`

It seems like this is an optimization that QuillJS is doing behind the scenes - is there anyway I can turn it off, so that I can keep both nested `span`s?