public function getChildClasses(string $qualifiedClassName)
    {
        $arrOptions = [];

        foreach (get_declared_classes() as $strName) {
            if (\in_array($qualifiedClassName, $this->getParentClasses($strName))) {
                $arrOptions[$strName] = $strName;
            }
        }

        asort($arrOptions);

        return $arrOptions;
    }