code: def set_transient(self, transient_view):
          
          top = self.get_top_widget()
          if isinstance(top, (list, tuple)):
              for t in top:
                  if t is not None:
                      transient_view.get_top_widget().set_transient_for(t)
          elif top is not None:
              transient_view.get_top_widget().set_transient_for(top)
docs: Set ``transient_view.get_top_widget()`` transient for
          ``self.``:meth:`get_top_widget`.