getCover method
This function getCover is called implicit but can also be called
from outside to load a cover as Uint8List. If there is no cover it
returns an empty Uint8List. Use coverId
to specify it's OL ID and
coverSize
S/M/L CoverSize to load
Implementation
Future<Uint8List> getCover(
{required int coverId, required CoverSize coverSize}) async {
final Uint8List cover = await _openLibraryApiService.getCoverById(
id: coverId.toString(), size: coverSize.name);
return cover;
}