protected function buildRequestEnvelope( RequestEnvelope $requestEnvelope , AbstractPayPalMessageFactory $factory ) {
		$requestEnvelopeElement = $factory->createMessageElement();
		$requestEnvelopeElement->addChild( $factory->createMessageField( 'errorLanguage' , $factory->createMessagePrimitive( $requestEnvelope->getErrorLanguage() ) ) );
		$requestEnvelopeElement->addChild( $factory->createMessageField( 'detailLevel' , $factory->createMessagePrimitive( $requestEnvelope->getDetailLevel() ) ) );

		return $requestEnvelopeElement;
	}