protected function build()
 {
     if ($this->task) {
         $this->where[] = " task_log.extension_id = :extension_id AND task_log.task_id = :task_id ";
         $this->params['task_id'] = $this->task->getTaskId();
         $this->params['extension_id'] = $this->task->getExtensionId();
     }
 }