public function reset($id = null) {
		$fields = [
			'completed' => null,
			'fetched' => null,
			'progress' => 0,
			'failed' => 0,
			'workerkey' => null,
			'failure_message' => null,
		];
		$conditions = [
			'completed IS' => null,
		];
		if ($id) {
			$conditions['id'] = $id;
		}

		return $this->updateAll($fields, $conditions);
	}