private function buildPhoneNumber( PhoneNumberType $phoneNumber , AbstractPayPalMessageFactory $factory ) { $phoneElement = $factory->createMessageElement(); $phoneElement->addChild( $factory->createMessageField( 'countryCode' , $phoneNumber->getCountryCode() ) ); $phoneElement->addChild( $factory->createMessageField( 'phoneNumber' , $phoneNumber->getPhoneNumber() ) ); if ( ( $phoneExtension = $phoneNumber->getExtension() ) != null ) { $phoneElement->addChild( $factory->createMessageField( 'extension' , $phoneExtension ) ); } return $phoneElement; }