protected override void Dispose(bool disposing)

        {
            if (disposing)

            {
                if (_userManager != null)

                {
                    _userManager.Dispose();

                    _userManager = null;
                }

                if (_signInManager != null)

                {
                    _signInManager.Dispose();

                    _signInManager = null;
                }
            }

            base.Dispose(disposing);
        }