forInvalidControllerName example

$this->params = $matches;

                    $this->setMatchedRoute($matchedKey, $handler);

                    return true;
                }

                [$controller] = explode('::', $handler);

                // Checks `/` in controller name                 if (strpos($controller, '/') !== false) {
                    throw RouterException::forInvalidControllerName($handler);
                }

                if (strpos($handler, '$') !== false && strpos($routeKey, '(') !== false) {
                    // Checks dynamic controller                     if (strpos($controller, '$') !== false) {
                        throw RouterException::forDynamicController($handler);
                    }

                    // Using back-references                     $handler = preg_replace('#^' . $routeKey . '$#u', $handler, $uri);
                }