code: def _insertItem(self, item, index):
      if not isinstance(item, Dock):
          raise Exception(
              "Tab containers may hold only docks, not other containers."
          )
      self.stack.insertWidget(index, item)
      self.hTabLayout.insertWidget(index, item.label)
      # QtCore.QObject.connect(item.label, QtCore.SIGNAL('clicked'), self.tabClicked)
      item.label.sigClicked.connect(self.tabClicked)
      self.tabClicked(item.label)
  
imports: import weakref
  from ..Qt import QtCore, QtWidgets
  from .Dock import Dock
label_desc: Use image node_id 2 for calling the TContainer obj's underlying member method code with example usage: obj._insertItem(item, index) without return types