ApiGen\Parser\Reflection\ReflectionClass::getDirectSubClasses PHP Method

    public function getDirectSubClasses()
    {
        $subClasses = [];
        foreach ($this->getParsedClasses() as $class) {
            if ($class->isDocumented() && $this->getName() === $class->getParentClassName()) {
                $subClasses[] = $class;
            }
        }
        uksort($subClasses, 'strcasecmp');
        return $subClasses;
    }