See below simplified Router class.

namespace Phalcon\Mvc;

class Router
{
    protected action = null;
    
    /**
     * Returns the processed action name
     */
    public function getActionName() -> string
    {
        return this->action;
    }
}

This class will return null when getActionName() is called even when our return type specifies it as a string. I'm expecting a Fatal error: Uncaught TypeError.
It would be nice if our static code analyser / compiler would detect that our member variable is incompatible.