/**
     * Returns the Handler
     *
     * @param string $identifier
     * @param \eZ\Publish\SPI\Persistence\FieldType $fieldType
     * @param \eZ\Publish\Core\Persistence\Legacy\Content\FieldValue\Converter $fieldValueConverter
     * @param \eZ\Publish\SPI\FieldType\FieldStorage $externalStorage
     *
     * @return \eZ\Publish\SPI\Persistence\Handler
     */
    protected function getHandler( $identifier, $fieldType, $fieldValueConverter, $externalStorage )
    {
        /** @var \eZ\Publish\Core\Persistence\FieldTypeRegistry $fieldTypeRegistry */
        $fieldTypeRegistry = self::$container->get( "ezpublish.persistence.field_type_registry" );
        /** @var \eZ\Publish\Core\Persistence\Legacy\Content\FieldValue\ConverterRegistry $converterRegistry */
        $converterRegistry = self::$container->get( "ezpublish.persistence.legacy.field_value_converter.registry" );
        /** @var \eZ\Publish\Core\Persistence\Legacy\Content\StorageRegistry $storageRegistry */
        $storageRegistry = self::$container->get( "ezpublish.persistence.external_storage_registry" );

        $textLineFieldType = new \eZ\Publish\Core\FieldType\TextLine\Type();
        $textLineFieldType->setTransformationProcessor( $this->getTransformationProcessor() );
        $textLineFieldValueConverter = new Legacy\Content\FieldValue\Converter\TextLine();

        $fieldTypeRegistry->register( "ezstring", $textLineFieldType );
        $converterRegistry->register( "ezstring", $textLineFieldValueConverter );

        $fieldTypeRegistry->register( $identifier, $fieldType );
        $converterRegistry->register( $identifier, $fieldValueConverter );
        $storageRegistry->register( $identifier, $externalStorage );

        return self::$container->get( "ezpublish.spi.persistence.legacy" );
    }
 /**
  * Gets the 'ezpublish.fieldtype.ezstring' service.
  *
  * This service is shared.
  * This method always returns the same instance of the service.
  *
  * @return eZ\Publish\Core\FieldType\TextLine\Type A eZ\Publish\Core\FieldType\TextLine\Type instance.
  */
 protected function getEzpublish_Fieldtype_EzstringService()
 {
     $this->services['ezpublish.fieldtype.ezstring'] = $instance = new \eZ\Publish\Core\FieldType\TextLine\Type();
     $instance->setTransformationProcessor($this->get('ezpublish.api.storage_engine.transformation_processor'));
     return $instance;
 }