load method
Load translations for locale.
The map may be nested, in which case it is flattened into dot-separated
keys when merged - see AssetLocalizations.flatten. Returning a flat
Map<String, String> remains valid.
Implementation
@override
Future<Map<String, dynamic>> load(Locale locale) async =>
(map.containsKey(locale.languageCode)) ? map[locale.languageCode]! : {};