Wallmander\ElasticsearchIndexer\Model\Query\WpConverter::argCat PHP Method

    public static function argCat(Query $query, $value, &$q)
    {
        /*
         * See https://codex.wordpress.org/Class_Reference/WP_Query#Category_Parameters
         */
        $in = [];
        $notIn = [];
        foreach ($value as $id) {
            if ((int) $id < 0) {
                $notIn[] = -$id;
            } else {
                $in[] = $id;
            }
        }
        if ($in) {
            $query->where('terms.category.term_id', $in);
        }
        if ($notIn) {
            $query->whereNot('terms.category.term_id', $notIn);
        }
    }