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; }