public Dictionary <Guid, string> GetUserDictionary(bool respectPermissions = true, bool includeEmptyKey = false)
        {
            var currentUser = loginService.GetCurrentUser();
            Dictionary <Guid, string> result;

            if (respectPermissions && currentUser.Role != UserRole.Admin)
            {
                result = userService.GetQueryable().Where(x => x.Id == currentUser.Id || x.CalendarVisibleToOthers).ToDictionary(x => x.Id, x => x.FriendlyName);
            }
            else
            {
                result = userService.Get().ToDictionary(x => x.Id, x => x.FriendlyName);
            }

            if (includeEmptyKey)
            {
                result[Guid.Empty] = "";
            }

            return(result);
        }