private async Task InternalLoginAsync(HttpContextBase context, ApplicationUser user, bool isPersistent)
{
var authenticationManager = GetAuthenticationManager(context);
authenticationManager.SignOut(DefaultAuthenticationTypes.ExternalCookie);
var identity = await user.GenerateUserIdentityAsync(userManager, userRoles);
authenticationManager.SignIn(new AuthenticationProperties { IsPersistent = isPersistent }, identity);
}
