public function build($inResponseTo)
    {

        $spData = $this->_settings->getSPData();
        $idpData = $this->_settings->getIdPData();

        $this->id = OneLogin_Saml2_Utils::generateUniqueID();
        $issueInstant = OneLogin_Saml2_Utils::parseTime2SAML(time());

        $spEntityId = htmlspecialchars($spData['entityId'], ENT_QUOTES);
        $logoutResponse = <<<LOGOUTRESPONSE
<samlp:LogoutResponse xmlns:samlp="urn:oasis:names:tc:SAML:2.0:protocol"
                  xmlns:saml="urn:oasis:names:tc:SAML:2.0:assertion"
                  ID="{$this->id}"
                  Version="2.0"
                  IssueInstant="{$issueInstant}"
                  Destination="{$idpData['singleLogoutService']['url']}"
                  InResponseTo="{$inResponseTo}"
                  >
    <saml:Issuer>{$spEntityId}</saml:Issuer>
    <samlp:Status>
        <samlp:StatusCode Value="urn:oasis:names:tc:SAML:2.0:status:Success" />
    </samlp:Status>
</samlp:LogoutResponse>
LOGOUTRESPONSE;
        $this->_logoutResponse = $logoutResponse;
    }