public async Task <IUserContext> GetUserByEmail(string emailAddress, CancellationToken cancellationToken = default(CancellationToken))
        {
            cancellationToken.ThrowIfCancellationRequested();

            var user = await _userManager.FindByEmailAsync(emailAddress);

            if (user == null)
            {
                return(null);
            }

            return(new UserContext(user));
        }