protected virtual async Task <IEnumerable <Claim> > SetAccountEmailAsync(TKey userID, IEnumerable <Claim> claims)
        {
            var email = claims.FirstOrDefault(x => x.Type == Constants.ClaimTypes.Email);

            if (email != null)
            {
                var userEmail = await userManager.GetEmailAsync(userID);

                if (userEmail == null)
                {
                    // if this fails, then presumably the email is already associated with another account
                    // so ignore the error and let the claim pass thru
                    var result = await userManager.SetEmailAsync(userID, email.Value);

                    if (result.Succeeded)
                    {
                        var email_verified = claims.FirstOrDefault(x => x.Type == Constants.ClaimTypes.EmailVerified);
                        if (email_verified != null && email_verified.Value == "true")
                        {
                            var token = await userManager.GenerateEmailConfirmationTokenAsync(userID);

                            await userManager.ConfirmEmailAsync(userID, token);
                        }

                        var emailClaims = new string[] { Constants.ClaimTypes.Email, Constants.ClaimTypes.EmailVerified };
                        return(claims.Where(x => !emailClaims.Contains(x.Type)));
                    }
                }
            }

            return(claims);
        }