private void OnProject_WritingSystemChanged(object sender, WeSayWordsProject.StringPair pair)
 {
     foreach (var task in ICareThatWritingSystemIdChangedTasks)
     {
         task.OnWritingSystemIdChanged(pair.from, pair.to);
     }
 }
 private void OnProject_MeaningFieldChanged(object sender, WeSayWordsProject.StringPair pair)
 {
     foreach (var task in Tasks.OfType <ICareThatMeaningFieldChanged>())
     {
         task.OnMeaningFieldChanged(pair.from, pair.to);
     }
 }