public async Task <User> FindByEmailPassword(string email, string password)
        {
            var filter = Builders <User> .Filter.Eq("Email", email);

            User user = await this._usersCollection
                        .Find <User>(filter)
                        .FirstOrDefaultAsync <User>();

            LogCosmosDBRequestCharge();

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

            bool passMatch = SecurityUtils.CheckMatch(user.Password, password);

            if (passMatch != true)
            {
                return(null);
            }
            else
            {
                return(user);
            }
        }