docs: def _create_temporary_connection(self):
          """Creates a placeholder connection view
  
          :return: New placeholder connection
          :rtype: rafcon.gui.mygaphas.items.connection.ConnectionPlaceholderView
          """
          if self._is_transition:
              self._connection_v = TransitionPlaceholderView(self._parent_state_v.hierarchy_level)
          else:
              self._connection_v = DataFlowPlaceholderView(self._parent_state_v.hierarchy_level)
          self.view.canvas.add(self._connection_v, self._parent_state_v)