How to stop a task

How do i stop a task i have looked in this forum but havent found anything that works with my code

PHP:

<?php

namespace besher\timer;

use besher\timer\Main;

use pocketmine\scheduler\Task;
use pocketmine\level\sound\ClickSound;
use pocketmine\level\sound\BlazeShootSound;

class SecondTask extends Task{
   
    public $time = 10; // Count down set to 10
   
    public function __construct(Main $main){
        $this->main = $main;
    }
   
    public function onRun(int $currentTick){
        foreach($this->main->getServer()->getOnlinePlayers() as $player){
        $this->time--;
        $player->sendTip("Time: ".$this->time);
        $player->getLevel()->addSound(new ClickSound($player));
        if($this->time == 1) $player->getLevel()->addSound(new BlazeShootSound($player));
        if($this->time == 0) $this->plugin->getScheduler()->cancelTask($this->getTaskId());
        }
    }
}

That just makes the server crash

 

Send crash and backtrace.

 

$this->plugin is not defined

 

How do i do that could you post the code?

 

PHP:

<?php

namespace besher\timer;

use besher\timer\Main;

use pocketmine\scheduler\Task;
use pocketmine\level\sound\ClickSound;
use pocketmine\level\sound\BlazeShootSound;

class SecondTask extends Task{
 
    public $time = 10; // Count down set to 10
 
    public function __construct(Main $main){
        $this->main = $main;
    }
 
    public function onRun(int $currentTick){
        foreach($this->main->getServer()->getOnlinePlayers() as $player){
        $this->time--;
        $player->sendTip("Time: ".$this->time);
        $player->getLevel()->addSound(new ClickSound($player));
        if($this->time == 1) $player->getLevel()->addSound(new BlazeShootSound($player));
        if($this->time == 0) $this->main->getScheduler()->cancelTask($this->getTaskId());
        }
    }
}