pocketmine\event\entity\EntityShootBowEvent::setProjectile PHP Method

    public function setProjectile(Entity $projectile)
    {
        if ($projectile !== $this->projectile) {
            if (count($this->projectile->getViewers()) === 0) {
                $this->projectile->kill();
                $this->projectile->close();
            }
            $this->projectile = $projectile;
        }
    }

 public function onEntityShootBow(EntityShootBowEvent $event)
 {
     if (!$event->isCancelled()) {
         $arrow = $event->getProjectile();
         $set = [$arrow->chunk, $arrow->nametag, $p];
         $newArrow = new AbilityArrow(...$set);
         $p = $event->getEntity();
         if ($p instanceof Player) {
             if (!$p->isCreative()) {
                 $list = [1 => FireArrow::class, 5 => TeleportArrow::class, 7 => SpiderArrow::class, 9 => HealArrow::class, 12 => PowerArrow::class];
                 $inv = $p->getInventory();
                 foreach ($inv->getContents() as $k => $i) {
                     $d = $i->getDamage();
                     if ($i->getID() == 351 && isset($list[$d])) {
                         $i->setCount($i->getCount() - 1);
                         $inv->setItem($k, $i);
                         $p->sendMessage([1 => "FireArrow", 5 => "TeleportArrow", 7 => "SpiderArrow", 9 => "HealArrow", 12 => "PowerArrow"][$d]);
                         $newArrow = new $list[$d](...$set);
                         break;
                     }
                 }
             }
         }
         $event->setProjectile($newArrow);
     }
 }