code: static void appendDot(Node n, ControlFlowGraph<Node> inCFG,
        Appendable builder) throws IOException {
      new DotFormatter(n, inCFG, builder, false);
    }
docs: Converts an AST to dot representation and appends it to the given buffer.
  @param n the root of the AST described in the dot formatted string
  @param inCFG Control Flow Graph.
  @param builder A place to dump the graph.