code: def setup_sort_column(widget, column=0, attribute=None, model=None):
      
      if not attribute:
          attribute = widget.get_name()
          if attribute is None:
              raise TypeError("Column not named")
      widget.connect('clicked', _clicked, column, attribute, model)
docs: *model* is the :class:`TreeModelSort` to act on. Defaults to what is
      displayed. Pass this if you sort before filtering.
  
      *widget* is a clickable :class:`TreeViewColumn`.
  
      *column* is an integer addressing the column in *model* that holds your
      objects.
  
      *attribute* is a string naming an object attribute to display. Defaults
      to the name of *widget*.