import 'package:configurable/configuration_provider.dart'; class SimpleConfigurationProvider implements ConfigurationProvider { Map configs = {}; @override String? getOrNull(String key, {String? defaultValue}) { var value = configs[key]; if (value == null) { configs[key] = defaultValue; return defaultValue; } return value; } @override bool containsKey(String key) { return configs.containsKey(key); } }