Why is [_parse_polygon_annotation()](https://github.com/NKI-AI/slidescore-api/blob/8eb91eb5c0ba7b01cfc1ad491d8fe4a7e31665a2/slidescore_api/utils/annotations.py#L217) returning a `MultiPolygon` object?
Why is _parse_polygon_annotation() returning a
MultiPolygonobject?