FilterInterface.php

<?php

namespace Drupal\Core\Routing;

use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\Routing\RouteCollection;

/**
 * A route filter service to filter down the collection of route instances.
 */
interface FilterInterface {
    
    /**
     * Filters the route collection against a request.
     *
     * @param \Symfony\Component\Routing\RouteCollection $collection
     *   The collection against which to match.
     * @param \Symfony\Component\HttpFoundation\Request $request
     *   A Request object against which to match.
     *
     * @return \Symfony\Component\Routing\RouteCollection
     *   A non-empty RouteCollection of matched routes
     *
     * @throws \Symfony\Component\Routing\Exception\ResourceNotFoundException
     *   If none of the routes in $collection matches $request. This is a
     *   performance optimization to not continue the match process when a match
     *   will no longer be possible.
     */
    public function filter(RouteCollection $collection, Request $request);

}