Pocketmine getLevels i not find please

foreach ($this->getServer()->getLevels() as $level) {
foreach ($level->getEntities() as $entity) {
if ($entity instanceof TradeNPC) {
file_put_contents($this->getDataFolder() . $entity->getNameTag() . ".dat", $entity->getSaveNBT());

 

PHP:

$this->getServer()->getWorldManager()->getWorlds()


 

PHP:

foreach ($this->getServer()->->getWorldManager()->getWorlds() as $world) {
foreach ($world->getEntities() as $entity) {
if ($entity instanceof TradeNPC) {
file_put_contents($this->getDataFolder() . $entity->getNameTag() . ".dat", $entity->getSaveNBT());
    }
  }
}