Configuration:
- PDF.js version: 2.0.550

Steps to reproduce the problem:
1. Render document in SVG mode `renderMode="svg"`

What is the expected behavior? (add screenshot)
Rendering annotations same way as they rendered on canvas

What went wrong? (add screenshot)
```
Warning: Unimplemented operator beginAnnotations
Warning: Unimplemented operator endAnnotations
```
}
      let appearance;
      if (value) {
        appearance = this.checkedAppearance;
      } else {
        appearance = this.uncheckedAppearance;
      }
      if (appearance) {
        const savedAppearance = this.appearance;
        this.appearance = appearance;
        const operatorList = super.getOperatorList(
          evaluator,
          task,
          renderForms,
          annotationStorage
        );
        this.appearance = savedAppearance;
        return operatorList;
      }
      
      return Promise.resolve(new OperatorList());
    }
    return super.getOperatorList(
      evaluator,
      task,
      renderForms,
      annotationStorage
    );
  }
  async save(evaluator, task, annotationStorage) {