clear method
Clear all values
Implementation
@override
FutureOr<bool> clear() async {
var result = true;
if (prefix == '') {
result = await sharedPreferences.clear();
} else {
for (final key in sharedPreferences.getKeys()) {
if (key.startsWith(prefix)) {
if (!await sharedPreferences.remove('$prefix$key')) {
result = false;
}
}
}
}
super.clear();
return result;
}