diff --git a/core/lib/Drupal/Core/Routing/AccessAwareRouter.php b/core/lib/Drupal/Core/Routing/AccessAwareRouter.php
index 76a9477..5c3d931 100644
--- a/core/lib/Drupal/Core/Routing/AccessAwareRouter.php
+++ b/core/lib/Drupal/Core/Routing/AccessAwareRouter.php
@@ -7,7 +7,6 @@
 use Drupal\Core\Session\AccountInterface;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpKernel\Exception\AccessDeniedHttpException;
-use Symfony\Component\Routing\Generator\Dumper\GeneratorDumperInterface;
 use Symfony\Component\Routing\Matcher\RequestMatcherInterface;
 use Symfony\Component\Routing\RequestContext as SymfonyRequestContext;
 use Symfony\Component\Routing\RequestContextAwareInterface;
diff --git a/core/lib/Drupal/Core/Routing/Router.php b/core/lib/Drupal/Core/Routing/Router.php
index 58f6fb3..f1e280b 100644
--- a/core/lib/Drupal/Core/Routing/Router.php
+++ b/core/lib/Drupal/Core/Routing/Router.php
@@ -10,7 +10,7 @@
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\Routing\Exception\MethodNotAllowedException;
 use Symfony\Component\Routing\Exception\ResourceNotFoundException;
-use Symfony\Component\Routing\Generator\UrlGeneratorInterface;
+use Symfony\Component\Routing\Generator\UrlGeneratorInterface as BaseUrlGeneratorInterface;
 use Symfony\Component\Routing\Matcher\RequestMatcherInterface;
 use Symfony\Component\Routing\RouteCollection;
 use Symfony\Component\Routing\RouterInterface;
@@ -23,20 +23,22 @@
  *
  * It consists of several steps, of which each are explained in more details
  * below:
- *   1. Get a collection of routes which potentially match the current request:
- *     This is done by the route provider, see ::getInitialRouteCollection().
- *   2. Filter the collection down further more. For example this filters out
- *     routes applying to other formats: See ::applyRouteFilters()
- *   3. Find the best matching route out of the remaining ones, by applying a
- *     regex: See ::matchCollection().
- *   4. Enhance the list of route attributes, for example loading entity objects
- *     See ::applyRouteEnhancers().
+ * 1. Get a collection of routes which potentially match the current request.
+ *    This is done by the route provider. See ::getInitialRouteCollection().
+ * 2. Filter the collection down further more. For example this filters out
+ *    routes applying to other formats: See ::applyRouteFilters()
+ * 3. Find the best matching route out of the remaining ones, by applying a
+ *    regex. See ::matchCollection().
+ * 4. Enhance the list of route attributes, for example loading entity objects.
+ *    See ::applyRouteEnhancers().
  *
  * This implementation uses ideas of the following routers:
+ * - \Symfony\Cmf\Component\Routing\DynamicRouter
+ * - \Drupal\Core\Routing\UrlMatcher
+ * - \Symfony\Cmf\Component\Routing\NestedMatcher\NestedMatcher
  *
  * @see \Symfony\Cmf\Component\Routing\DynamicRouter
  * @see \Drupal\Core\Routing\UrlMatcher
- * @see \Symfony\Cmf\Component\Routing\NestedMatcher\NestedMatcher
  */
 class Router extends UrlMatcher implements RequestMatcherInterface, RouterInterface {
 
@@ -92,7 +94,7 @@ class Router extends UrlMatcher implements RequestMatcherInterface, RouterInterf
    * @param \Symfony\Component\Routing\Generator\UrlGeneratorInterface $url_generator
    *   The URL generator.
    */
-  public function __construct(BaseRouteProviderInterface $route_provider, CurrentPathStack $current_path, UrlGeneratorInterface $url_generator) {
+  public function __construct(BaseRouteProviderInterface $route_provider, CurrentPathStack $current_path, BaseUrlGeneratorInterface $url_generator) {
     parent::__construct($current_path);
     $this->routeProvider = $route_provider;
     $this->urlGenerator = $url_generator;
@@ -170,7 +172,7 @@ protected function getInitialRouteCollection(Request $request) {
   }
 
   /**
-   * Apply the route enhancers to the defaults, according to priorities
+   * Apply the route enhancers to the defaults, according to priorities.
    *
    * @param array $defaults
    *   The defaults coming from the final matched route.