public void DisposeViewModel(IMainViewModel viewModelToDispose)
{
viewModelCommunication.RemoveViewModelCollection(Constants.ViewModelCollections.TherapyPlaceRowViewModelCollection);
viewModelCommunication.RemoveViewModelCollection(Constants.ViewModelCollections.AppointmentGridViewModelCollection);
viewModelCommunication.RemoveViewModelCollection(Constants.ViewModelCollections.TimeGridViewModelCollection);
viewModelCommunication.RemoveViewModelCollection(Constants.ViewModelCollections.AppointmentViewModelCollection);
var optionsPageViewModel = viewModelToDispose.OptionsPageViewModel;
var searchPageViewModel = viewModelToDispose.SearchPageViewModel;
var overviewPageViewModel = viewModelToDispose.OverviewPageViewModel;
var patientSelectorViewModel = searchPageViewModel.PatientSelectorViewModel;
var dateDisplayViewModel = overviewPageViewModel.DateDisplayViewModel;
var medicalPracticeSelectorViewModel = overviewPageViewModel.MedicalPracticeSelectorViewModel;
var roomSelectorViewModel = overviewPageViewModel.RoomFilterViewModel;
var dateSelectorViewModel = overviewPageViewModel.DateSelectorViewModel;
var gridContainerViewModel = overviewPageViewModel.GridContainerViewModel;
var undoRedoViewModel = overviewPageViewModel.UndoRedoViewModel;
viewModelCommunication.DeregisterViewModelMessageHandler <AsureDayIsLoaded>(gridContainerViewModel);
viewModelCommunication.DeregisterViewModelMessageHandler <ShowPage>(viewModelToDispose);
viewModelCommunication.DeregisterViewModelMessageHandler(confirmChangesMessageHandler);
viewModelCommunication.DeregisterViewModelMessageHandler(rejectChangesMessageHandler);
optionsPageViewModel.Dispose();
searchPageViewModel.Dispose();
overviewPageViewModel.Dispose();
patientSelectorViewModel.Dispose();
dateDisplayViewModel.Dispose();
medicalPracticeSelectorViewModel.Dispose();
roomSelectorViewModel.Dispose();
dateSelectorViewModel.Dispose();
gridContainerViewModel.Dispose();
undoRedoViewModel.Dispose();
}