public function setPasswordHash($passwordHash)
    {
        if ($passwordHash === null) {
            $this->hashedPassword = null;
            return;
        }

        // check that the password hash is valid (sanity check)
        UsersManager::checkPasswordHash($passwordHash, Piwik::translate('Login_ExceptionPasswordMD5HashExpected'));

        $this->hashedPassword = $passwordHash;
    }