private bool CheckIfModelExistsInSameGroup(IEnumerable<NodeModel> selectNodes, IEnumerable<NoteModel> selectNotes) { var selectedModels = selectNodes.Concat(selectNotes.Cast<ModelBase>()).ToList(); bool nodesInSameGroup = false; foreach (var group in this.Annotations) { var groupModels = group.SelectedModels; nodesInSameGroup = !selectedModels.Except(groupModels).Any(); if (nodesInSameGroup) break; } return nodesInSameGroup; }