The type or namespace name 'Xunit' could not be found (are you missing a using directive or an assembly reference?)

The type or namespace name 'Graph_Data' could not be found (are you missing a using directive or an assembly reference?)

The type or namespace name 'Graph_Data' could not be found (are you missing a using directive or an assembly reference?)

The type or namespace name 'Graph<,,>' could not be found (are you missing a using directive or an assembly reference?)

The type or namespace name 'Graph_Data' could not be found (are you missing a using directive or an assembly reference?)

The type or namespace name 'Node<,,>' could not be found (are you missing a using directive or an assembly reference?)

The name 'ResourceDictionaryLocation' does not exist in the current context

The name 'ResourceDictionaryLocation' does not exist in the current context

The type or namespace name 'ThemeInfo' could not be found (are you missing a using directive or an assembly reference?)

The type or namespace name 'ThemeInfoAttribute' could not be found (are you missing a using directive or an assembly reference?)

Cannot convert null literal to non-nullable reference type.

Nullability of reference types in type of 'event PropertyChangedEventHandler ViewModelBase.PropertyChanged' doesn't match implicitly implemented member 'event PropertyChangedEventHandler? INotifyPropertyChanged.PropertyChanged'.

The type 'TKey' cannot be used as type parameter 'TKey' in the generic type or method 'Dictionary<TKey, TValue>'. Nullability of type argument 'TKey' doesn't match 'notnull' constraint.

Cannot convert null literal to non-nullable reference type.

Nullability of reference types in type of 'event PropertyChangedEventHandler ViewModelBase.PropertyChanged' doesn't match implicitly implemented member 'event PropertyChangedEventHandler? INotifyPropertyChanged.PropertyChanged'.