public function createUser($accountID, $contactID, $username, $password)
    {
        try
        {
            return $this->httpHelper->patch("accounts/" . intval($accountID) . "/contacts/" . intval($contactID),[
                'username' => $username,
                'password' => $password
            ]);
        }
        catch (ApiException $e)
        {
            throw new InvalidArgumentException($e->getMessage());
        }
    }