Illuminate\Routing\Router::parseMiddlewareGroup PHP Method

    protected function parseMiddlewareGroup($name)
    {
        $results = [];
        foreach ($this->middlewareGroups[$name] as $middleware) {
            // If the middleware is another middleware group we will pull in the group and
            // merge its middleware into the results. This allows groups to conveniently
            // reference other groups without needing to repeat all their middlewares.
            if (isset($this->middlewareGroups[$middleware])) {
                $results = array_merge($results, $this->parseMiddlewareGroup($middleware));
                continue;
            }
            list($middleware, $parameters) = array_pad(explode(':', $middleware, 2), 2, null);
            // If this middleware is actually a route middleware, we will extract the full
            // class name out of the middleware list now. Then we'll add the parameters
            // back onto this class' name so the pipeline will properly extract them.
            if (isset($this->middleware[$middleware])) {
                $middleware = $this->middleware[$middleware];
            }
            $results[] = $middleware . ($parameters ? ':' . $parameters : '');
        }
        return $results;
    }