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