public async Task <ActionResult> Index()
        {
            try
            {
                GraphServiceClient graphClient = GraphHelper.GetAuthenticatedClient();

                //TODO: Retrieve Conversations to be displayed
                //  https://graph.microsoft.com/v1.0/groups?filter=displayname eq 'maintenance'
                var maintGroupId = await GroupHelper.GetGroupIdAsync("Visitor Intake");

                //https://graph.microsoft.com/v1.0/groups/{id}/conversations
                IList <Conversation> maintConversations = await GroupHelper.GetGroupConversationsAsync(maintGroupId);

                ViewBag.GroupId = maintGroupId;
                return(View(maintConversations));
            }
            catch (ServiceException se)
            {
                return(RedirectToAction("Index", "Error", new { message = Request.RawUrl + ": " + se.Error.Message }));
            }
        }