loadPublication method
Load publication manifest from URL, which is usually a packaged ebook or direct URL to a manifest.
This will NOT store a reference to the Publication and is purely meant to be used for fetching metadata/manifest
for multiple books. It never affects the open publication, even when pubUrl is the URL of the open one.
Implementation
@override
Future<Publication> loadPublication(String pubUrl) async {
final publicationString = await methodChannel
.invokeMethod<String>('loadPublication', [pubUrl])
.then<String>((dynamic result) => result);
return Publication.fromJson(json.decode(publicationString) as Map<String, dynamic>)!;
}