code: def updatetext(self):
          
          if self.TEXTCONTAINER:
              s = ""
              for child in self:
                  if isinstance(child, AbstractElement):
                      child.updatetext()
                      s += child.text()
                  elif isstring(child):
                      s += child
              self.data = [s]
docs: Recompute textual value based on the text content of the children. Only supported on elements that are a ``TEXTCONTAINER``