system/CodeIgniter.php
protected function tryToRouteIt(RouteCollectionInterface $routes = null)
	{
		if (empty($routes) || ! $routes instanceof RouteCollectionInterface)
		{
			require APPPATH . 'Config/Routes.php';
		}

		// $routes is defined in Config/Routes.php
		$this->router = Services::router($routes);

		$path = $this->determinePath();

		$this->benchmark->stop('bootstrap');
		$this->benchmark->start('routing');

		ob_start();

		$this->controller = $this->router->handle($path);
		$this->method     = $this->router->methodName();

		// If a {locale} segment was matched in the final route,
		// then we need to set the correct locale on our Request.
		if ($this->router->hasLocale())
		{
			$this->request->setLocale($this->router->getLocale());
		}

		$this->benchmark->stop('routing');

		return $this->router->getFilter();
	}
protected function tryToRouteIt(RouteCollectionInterface $routes = null)
	{
		if (empty($routes) || ! $routes instanceof RouteCollectionInterface)
		{
			require APPPATH . 'Config/Routes.php';
		}

		// $routes is defined in Config/Routes.php
		$this->router = Services::router($routes);

		$path = $this->determinePath();

		$this->benchmark->stop('bootstrap');
		$this->benchmark->start('routing');

		ob_start();

		$this->controller = $this->router->handle($path);
		$this->method     = $this->router->methodName();

		// If a {locale} segment was matched in the final route,
		// then we need to set the correct locale on our Request.
		if ($this->router->hasLocale())
		{
			$this->request->setLocale($this->router->getLocale());
		}

		$this->benchmark->stop('routing');

		return $this->router->getFilter();
	}
Try to Route It - As it sounds like, works with the router to
match a route against the current URI. If the route is a
"redirect route", will also handle the redirect.

@param RouteCollectionInterface $routes An collection interface to use in place
of the config file.

@return string
@throws \CodeIgniter\Router\Exceptions\RedirectException