eZ\Publish\Core\Persistence\Legacy\Content\FieldValue\Converter\PageConverter::toStorageValue PHP Method

    public function toStorageValue(FieldValue $value, StorageFieldValue $storageFieldValue)
    {
        $storageFieldValue->dataText = $value->data === null ? null : $this->generateXmlString($value->data);
    }

 /**
  * Test converting Parts\Page to XML.
  */
 public function testToStorageValue()
 {
     $storageFieldValue = new StorageFieldValue();
     $fieldValue = new FieldValue(array('data' => $this->pageReference));
     $this->converter->toStorageValue($fieldValue, $storageFieldValue);
     $this->assertXmlStringEqualsXmlString(self::PAGE_XML_REFERENCE, $storageFieldValue->dataText);
 }