public SprintSelectorViewModel(Project project,
Func<Project,Sprint,ProjectDetailsViewModel> projectDetailsFactory,
ProjectRepository projectRepository,
IShell shell)
{
_project = project;
_projectDetailsFactory = projectDetailsFactory;
_projectRepository = projectRepository;
_shell = shell;
_projectRepository.GetSprintsObservable(_project).ToProperty(this, t => t.AllSprints, out allSprints);
}