content: import 'package:flutter/material.dart';
  
  import '../../repository/data_classes/settings/MensaColorScheme.dart';
  import '../../repository/data_classes/settings/MealPlanFormat.dart';
  import '../../repository/data_classes/settings/PriceCategory.dart';
  
  /// This is an interface for accessing the preferences.
  abstract class IPreferenceAccess with ChangeNotifier {
    /// Returns the client identifier.
    String getClientIdentifier();
  
    /// Sets the client identifier.
    Future<void> setClientIdentifier(String identifier);
  
    /// Returns the saved ColorScheme.
    MensaColorScheme getColorScheme();
  
    /// Sets the committed ColorScheme.
    Future<void> setColorScheme(MensaColorScheme scheme);
  
    /// Returns the saved PriceCategory.
    PriceCategory getPriceCategory();
  
    /// Sets the committed PriceCategory.
    Future<void> setPriceCategory(PriceCategory category);
  
    /// Returns the saved MealPlanFormat.
    MealPlanFormat getMealPlanFormat();
  
    /// Sets the committed MealPlanFormat.
    Future<void> setMealPlanFormat(MealPlanFormat format);
  }
  