public function traverseFilters(callable $callable)
    {
        foreach ($this->filters() as $expr) {
            /**
             * @param  FilterInterface           $expr The iterated filter expression object.
             * @param  FilterCollectionInterface $this The context of the traversal.
             * @return void
             */
            $callable($expr, $this);
            if ($expr instanceof FilterCollectionInterface) {
                $expr->traverseFilters($callable);
            }
        }

        return $this;
    }