/// <summary>
/// Init Group Hub api service, when invoking this, it will prompt a logon window, customer need to input the password
/// </summary>
/// <param name="region">region of your tenant</param>
/// <param name="office365TenantId">office 365 tenant id of your tenant</param>
/// <param name="userName">your user name</param>
private static void Initilize(Region region, String office365TenantId, String userName)
{
var clientId = "d3590ed6-52b3-4102-aeff-aad2292ab01c";
var redirectUri = "urn:ietf:wg:oauth:2.0:oob";
var resource = "https://graph.microsoft.com";
var authority = $"https://login.windows.net/{office365TenantId}";
var authenticationContext = new AuthenticationContext(authority);
var userId = new UserIdentifier(userName, UserIdentifierType.OptionalDisplayableId);
var result = authenticationContext.AcquireToken(resource, clientId, new Uri(redirectUri), PromptBehavior.Always, userId);
AuthenticationTokenModel model = new AuthenticationTokenModel();
model.AccessToken = result.AccessToken;
model.RefreshToken = result.RefreshToken;
GroupHubApi.Init(region, model);
}
