Method plus

src/main/java/groovy/util/Node.java:271–276

Adds sibling nodes (defined using builder-style notation via a Closure) after the current node. @param c A Closure defining the new sibling nodes to add using builder-style notation.

(Closure c)

     * @param c A Closure defining the new sibling nodes to add using builder-style notation.
     */
    public void plus(Closure c) {
        if (parent() == null) {
            throw new UnsupportedOperationException("Adding sibling nodes to the root node is not supported");
        }
        appendNodes(c);
    }

    private void appendNodes(Closure c) {
        List tail = getTail();