private protected async Task AuthorizeAsync(OAuth2App app, OAuth2EndPoint endPoint)
{
_app = app;
_endPoint = endPoint;
_credentials = await OAuth2Broker.AuthorizeAsync(app, endPoint).ConfigureAwait(false);
}
private protected async Task UpdateCredentialsAsync()
{
_credentials = await OAuth2Broker.UpdateCredentialsAsync(_credentials, _app, _endPoint).ConfigureAwait(false);
}