public function build()
    {
        $routeCollection = new RouteCollection();

        foreach ($this->routes as $name => $route) {
            if ($route instanceof Route) {
                $route->setDefaults(array_merge($this->defaults, $route->getDefaults()));
                $route->setOptions(array_merge($this->options, $route->getOptions()));

                foreach ($this->requirements as $key => $val) {
                    if (!$route->hasRequirement($key)) {
                        $route->setRequirement($key, $val);
                    }
                }

                if (null !== $this->prefix) {
                    $route->setPath('/'.$this->prefix.$route->getPath());
                }

                if (!$route->getHost()) {
                    $route->setHost($this->host);
                }

                if (!$route->getCondition()) {
                    $route->setCondition($this->condition);
                }

                if (!$route->getSchemes()) {
                    $route->setSchemes($this->schemes);
                }

                if (!$route->getMethods()) {
                    $route->setMethods($this->methods);
                }

                // auto-generate the route name if it's been marked
                if ('_unnamed_route_' === substr($name, 0, 15)) {
                    $name = $this->generateRouteName($route);
                }

                $routeCollection->add($name, $route);
            } else {
                /* @var self $route */
                $subCollection = $route->build();
                $subCollection->addPrefix($this->prefix);

                $routeCollection->addCollection($subCollection);
            }
        }

        foreach ($this->resources as $resource) {
            $routeCollection->addResource($resource);
        }

        return $routeCollection;
    }