Date::parse( string $date ): int|false

601    public function parse(string $date)602    {603        foreach ($this->user as $method) {604            if (($returned = call_user_func($method, $date)) !== false) {605                return (int) $returned;606            }607        }608 609        foreach ($this->built_in as $method) {610            // TODO: we should really check this in constructor but that would require private properties.611            /** @var callable(string): (int|false) */612            $callable = [$this, $method];613            if (($returned = call_user_func($callable, $date)) !== false) {614                return $returned;615            }616        }617 618        return false;619    }