FileDataStore fDS = new FileDataStore(Logger.Folder, true);
GoogleClientSecrets clientSecrets = GoogleClientSecrets.Load(stream);
credential = GoogleWebAuthorizationBroker.AuthorizeAsync(
                                clientSecrets.Secrets,
                                scopes.ToArray(),
                                username,
                                CancellationToken.None,
                                fDS).
                                Result;
var initializer = new Google.Apis.Services.BaseClientService.Initializer();
initializer.HttpClientInitializer = credential;