pocketmine\entity\Entity::setNameTagVisible PHP Method

    public function setNameTagVisible($value = true)
    {
        $this->setDataProperty(self::DATA_SHOW_NAMETAG, self::DATA_TYPE_BYTE, $value ? 1 : 0);
    }

 public function remove(Entity $entity)
 {
     if ($entity instanceof Player) {
         $pk = new MobEffectPacket();
         $pk->eid = 0;
         $pk->eventId = MobEffectPacket::EVENT_REMOVE;
         $pk->effectId = $this->getId();
         $entity->dataPacket($pk);
     }
     if ($this->id === Effect::INVISIBILITY) {
         $entity->setDataFlag(Entity::DATA_FLAGS, Entity::DATA_FLAG_INVISIBLE, false);
         $entity->setNameTagVisible(true);
     } elseif ($this->id === Effect::SPEED) {
         $attr = $entity->getAttributeMap()->getAttribute(Attribute::MOVEMENT_SPEED);
         $attr->setValue($attr->getValue() / (1 + 0.2 * $this->amplifier));
     } elseif ($this->id === Effect::SLOWNESS) {
         $attr = $entity->getAttributeMap()->getAttribute(Attribute::MOVEMENT_SPEED);
         $attr->setValue($attr->getValue() / (1 - 0.15 * $this->amplifier));
     }
 }