remove method
Removes content for given key
Implementation
Future<bool> remove(String key) async {
_listeners.forEach((listener) {
if (_listeners.contains(key as Object)) {
listener.keyRemove(key);
}
});
SharedPreferences prefs = await _getSharedPreferences();
if (prefs.containsKey(_withValidSuffix(key))) {
prefs.remove(_withValidSuffix(key));
}
return _remove(key);
}