code: def create_cell_renderer_combo(self, tree_view, title="title", assign=0, editable=False, model=None, function=None):
          
          renderer_combo = Gtk.CellRendererCombo()
          renderer_combo.set_property('editable', editable)
          if model:
              renderer_combo.set_property('model', model)
          if function:
              renderer_combo.connect("edited", function)
          renderer_combo.set_property("text-column", 0)
          renderer_combo.set_property("has-entry", False)
          column = Gtk.TreeViewColumn(title, renderer_combo, text=assign)
          tree_view.append_column(column)
docs: Function creates a CellRendererCombo with title, model