src/WorkerPool.php
public function next() {
		$this->collectWorkerResults();
		if (!empty($this->results)) {
			$this->resultPosition++;
		}
		array_shift($this->results);
	}
public function next() {
		$this->collectWorkerResults();
		if (!empty($this->results)) {
			$this->resultPosition++;
		}
		array_shift($this->results);
	}
Iterator Method next()