/// <summary>Called when authorization is required.</summary>
/// <param name="filterContext">An object that encapsulates the information that is required in order to authorize access to the transfer action.</param>
public void OnAuthorization(AuthorizationContext filterContext)
{
if (filterContext == null)
{
throw new ArgumentNullException(nameof(filterContext));
}
if (!filterContext.IsTransferAction())
{
throw new InvalidOperationException(string.Format("The action '{0}' is accessible only by a transfer request.", filterContext.ActionDescriptor.ActionName));
}
}