code: public void expandParamPanelNode(String panelName) {
          DefaultMutableTreeNode node = getTreeNodeFromPanelName(panelName);
          if (node != null) {
              getTreeParam().expandPath(new TreePath(node.getPath()));
          }
      }
docs: Expands the node of the param panel with the given name.
  
  @param panelName the name of the panel whose node should be expanded, should not be {@code null}.
  @since TODO add version