public function testToStorageValueEmpty()
{
$fieldValue = new FieldValue();
$fieldValue->data = array();
$fieldValue->sortKey = '';
$expectedStorageFieldValue = new StorageFieldValue();
$expectedStorageFieldValue->dataText = '';
$expectedStorageFieldValue->sortKeyString = '';
$actualStorageFieldValue = new StorageFieldValue();
$this->converter->toStorageValue($fieldValue, $actualStorageFieldValue);
$this->assertEquals($expectedStorageFieldValue, $actualStorageFieldValue);
}