lib/Query/Location/CriterionVisitor/FullText.php
public function visit(Criterion $criterion, CriterionVisitor $subVisitor = null)
    {
        $condition = $this->escapeQuote(parent::visit($criterion, $subVisitor));

        return "{!child of='document_type_id:content' v='document_type_id:content AND {$condition}'}";
    }
public function visit(Criterion $criterion, CriterionVisitor $subVisitor = null)
    {
        $condition = $this->escapeQuote(parent::visit($criterion, $subVisitor));

        return "{!child of='document_type_id:content' v='document_type_id:content AND {$condition}'}";
    }
Map field value to a proper Solr representation.

@param \eZ\Publish\API\Repository\Values\Content\Query\Criterion $criterion
@param \EzSystems\EzPlatformSolrSearchEngine\Query\CriterionVisitor $subVisitor

@return string