private void toggleGroup(final NodeType node) {
    final IGroupNode<?, ?> gnode = (IGroupNode<?, ?>) node.getRawNode();

    gnode.setCollapsed(!gnode.isCollapsed());
  }
Toggles the expansion state of a given group node.

@param node The node to expand or collapse.
java/zylib/src/main/java/com/google/security/zynamics/zylib/yfileswrap/gui/zygraph/editmode/actions/CDefaultNodeClickedLeftAction.java