code: def children(self):
          
          new_refs = set()
          output = []
          for ref in self._children:
              item = ref()
              if item is not None:
                  output.append(item)
                  new_refs.add(ref)
          
          self._children = new_refs
          return output
docs: Returns the children in this group.
          
          :return     [<QtGui.QListWidgetItem>, ..]