code: def getNodesCheckState(self, parentItem=None):
          
          if parentItem is None:
              parentItem = self.rootItem
  
          checkStates = odict()
          children = parentItem.getChildren()
  
          for child in children:
              checkStates[child.itemData[0]] = child.getCheckState()
  
          return checkStates
docs: Return the check state (disabled, tristate, enable) of all items
          belonging to a parent.