Unable to use _remap without default method in controller

[krishnan57474]

Describe the bug
A controller with method other than _remap
creates error in routes toolbar collector.

CodeIgniter 4 version
CodeIgniter4 Beta 0.0.2

Affected module(s)
system\Debug\Toolbar\Collectors\Routes.php

Expected behavior, and steps to reproduce if appropriate

1. Set CodeIgniter environment to development
2. Rename index method to _remap in app/Controllers/Home.php
3. run

You get method not exists error.

The following statement in system\Debug\Toolbar\Collectors\Routes.php:

    $method    = is_callable($router->controllerName()) ? new \ReflectionFunction($router->controllerName()) : new \ReflectionMethod($router->controllerName(), $router->methodName());

Calling \ReflectionMethod($router->controllerName(), $router->methodName()) without method_exists check
causes method not exists error.

Fix

    $method    = is_callable($router->controllerName()) ? new \ReflectionFunction($router->controllerName()) : new \ReflectionMethod($router->controllerName(), method_exists($router->controllerName(), '_remap') ? '_remap' : $router->methodName());

[jim-parry]

Unable to reproduce this specific problem.
Applying the proposed solution breaks ControllerTesterTest, which expects an index() method.
The user guide says that index() is the default method, hence it seems reasonable that not having it, whether or not you have a _remap(), would cause problems.