code: def append(self, row=None):
          
  
          if row:
              return self._do_insert(-1, row)
          # gtk_list_store_insert() does not know about the "position == -1"
          # case, so use append() here
          else:
              return Gtk.ListStore.append(self)
docs: append(row=None)
  
          :param row: a list of values to apply to the newly append row or :obj:`None`
          :type row: [:obj:`object`] or :obj:`None`
  
          :returns: :obj:`Gtk.TreeIter` of the appended row
          :rtype: :obj:`Gtk.TreeIter`
  
          If `row` is :obj:`None` the appended row will be empty and to fill in
          values you need to call :obj:`Gtk.ListStore.set`\\() or
          :obj:`Gtk.ListStore.set_value`\\().
  
          If `row` isn't :obj:`None` it has to be a list of values which will be
          used to fill the row .