docs: def startLoading(self):
          """
          Updates this item to mark the item as loading.  This will create
          a QLabel with the loading ajax spinner to indicate that progress
          is occurring.
          """
          if self._loading:
              return False
          
          tree = self.treeWidget()
          if not tree:
              return
          
          self._loading = True
          self.setText(0, '')
          
          # create the label for this item
          lbl = QtGui.QLabel(self.treeWidget())
          lbl.setMovie(XLoaderWidget.getMovie())
          lbl.setAlignment(QtCore.Qt.AlignCenter)
          tree.setItemWidget(self, 0, lbl)
          
          try:
              tree.loadStarted.emit(self)
          except AttributeError:
              pass
          
          return True