/**
  * Disable logging
  */
 protected function DisableLogging()
 {
     if (!$this->log) {
         return;
     }
     if ($this->projectList) {
         $this->projectList->RemoveObserver($this->log);
     }
     if ($this->exe) {
         $this->exe->RemoveObserver($this->log);
     }
     $this->log->SetEnabled(false);
     $this->log = null;
 }