code: def decoration(self):
          
          rtiIconFactory = RtiIconFactory.singleton()
  
          if self._exception:
              return rtiIconFactory.getIcon(rtiIconFactory.ERROR, isOpen=False,
                                            color=rtiIconFactory.COLOR_ERROR)
          else:
              return rtiIconFactory.getIcon(self.iconGlyph, isOpen=not self.canFetchChildren(),
                                            color=self.iconColor)
docs: The displayed icon.
  
              Shows open icon when node was visited (children are fetched). This allows users
              for instance to collapse a directory node but still see that it was visited, which
              may be useful if there is a huge list of directories.