getKeysF static method
Returns a Future.
Implementation
static Future<Set<String>> getKeysF() async {
Set<String> value;
if (_prefsInstance == null) {
final prefs = await instance;
value = prefs.getKeys();
} else {
// SharedPreferences is available. Ignore init() function.
_initCalled = true;
value = getKeys();
}
return value;
}