code: public String getAstDotGraph() throws IOException {
      if (jsRoot != null) {
        ControlFlowAnalysis cfa = new ControlFlowAnalysis(this, true, false);
        cfa.process(null, jsRoot);
        return DotFormatter.toDot(jsRoot, cfa.getCfg());
      } else {
        return "";
      }
    }
docs: Gets the DOT graph of the AST generated at the end of compilation.