content: /// This classes are exceptions that can occur by accessing or loading the meal plan.
  /// This happens with functional programming.
  
  /// This class is the superclass of all meal plan exceptions
  sealed class MealPlanException implements Exception {
    /// This constructor creates a new object
    const MealPlanException();
  }
  
  /// [NoConnectionException] is thrown if  the connection to the server can not be established.
  class NoConnectionException extends MealPlanException {
    /// The message of the exception.
    String message;
  
    /// This constructor creates a new [NoConnectionException] with the given message.
    NoConnectionException(this.message);
  }
  
  /// [ClosedCanteenException] is thrown if the selected canteen is closed on the selected day.
  class ClosedCanteenException extends MealPlanException {
    /// The message of the exception.
    String message;
  
    /// This constructor creates a new [ClosedCanteenException] with the given message.
    ClosedCanteenException(this.message);
  }
  
  /// [FilteredMealException] is thrown if no meal of the mealplan matches the filter preferences.
  class FilteredMealException extends MealPlanException {
    /// The message of the exception.
    String message;
  
    /// This constructor creates a new [FilteredMealException] with the given message.
    FilteredMealException(this.message);
  }
  
  /// [NoDataException] is thrown if the server does not have the requested data stored because the selected date is to far in the future or before the server started storing meal plans.
  class NoDataException extends MealPlanException {
    /// The message of the exception.
    String message;
  
    /// This constructor creates a new [NoDataException] with the given message.
    NoDataException(this.message);
  }
  