pocketmine\Thread::start PHP Method

    public function start(int $options = PTHREADS_INHERIT_ALL)
    {
        ThreadManager::getInstance()->add($this);
        if (!$this->isRunning() and !$this->isJoined() and !$this->isTerminated()) {
            if ($this->getClassLoader() === null) {
                $this->setClassLoader();
            }
            return parent::start($options);
        }
        return false;
    }