why CompoundTag can't call to method?

[Server thread/CRITICAL]: Error: "Call to undefined method pocketmine\nbt\tag\CompoundTag::multiply()"

if I use $nbt->multiply($i), it crash but when I use $directionVector->multiply($i), It works.
Why not CompoundTag?



1. for ($i=0; $i<10; $i++){
$pos = $nbt->multiply($i)->add($player);

2. for ($i=0; $i<10; $i++){
$pos = $directionVector->multiply($i)->add($player);

 

Because CompoundTag hasn't multiply() method. Maybe you wanted to use some Vector class...