public function createWorker($workingRangeFrom, $workingRangeTo)
 {
     $task = new Gpf_Mail_OutboxRunner();
     $this->debug('Creating new worker Gpf_Mail_OutboxRunner for range:' . $workingRangeFrom . '-' . $workingRangeTo);
     $task->setWorkingArea($workingRangeFrom, $workingRangeTo);
     $task->setParams($this->task->getParams());
     $task->insertTask();
 }