Solved dont place block

hi guys, my block is not put, why?
public function onProjectileHit(ProjectileHitEvent $event) {
$snowball = $event->getEntity();
$x = (int)round($snowball->getX());
$y = (int)round($snowball->getY());
$z = (int)round($snowball->getZ());
if($snowball instanceof Snowball){
$this->getServer()->getDefaultLevel()->setBlock(new Vector3($x, $y+1, $z),new Block(171,14));
}
}

 

There are two classes named Snowball in PocketMine. Which one are you importing?

 

What 2 classes ?? I have only 1 snowball in my folder with entity

 

How can I even make the installation of the unit after the snowball landing

 

pls, help me
public function onProjectileHit(ProjectileHitEvent $event) {
$snows = $event->getEntity();
if($snows instanceof CustomSnowball){
$this->getServer()->getDefaultLevel()->setBlock(new Vector3($snows->getPosition()),new Block(171,14));
}
}

 

Why is this thread marked as solved?

 

I'm very dull and do not understand how to make it so that the unit is delivered, I tried many things, still not at all!