Errors when using dot2texi in MikTeX

Question

I receive errors in log file while trying to compile the following code:

\documentclass{article}

\usepackage{tikz}
\usetikzlibrary{shapes,arrows}
\usepackage{dot2texi}

\begin{document}
  \begin{dot2tex}[neato,options=-tmath]
    digraph G {
      node [shape="circle"];
      a_1 -> a_2 -> a_3 -> a_4 -> a_1;
 }
\end{dot2tex}
\end{document}

It is an example from dot2tex website. An example of the error is:

Undefined control sequence \begin{dot2tex}[neato,options=-tmath]

The author of the package suggests on this link, that you should define

\@ifundefined{verbatim@out}{\newwrite\verbatim@out}{}%

inside your package, but I still cannot understand where should I put this command, because I am TeX-newbee.

FIX: I have put \@ifundefined{verbatim@out}{\newwrite\verbatim@out}{}% into dot2texi.sty right in the beginning:

\NeedsTeXFormat{LaTeX2e}[1999/12/01]
\ProvidesPackage{dot2texi}[2008/05/07 v3.0 Run dot2tex from LaTeX]
\RequirePackage{moreverb}
\RequirePackage{xkeyval}[2005/02/22]

\@ifundefined{verbatim@out}{\newwrite\verbatim@out}{}% 

\newif\ifdtt@ShellEscape
%\newif\ifmiktex \miktexfalse

Answer 1

Modifying style files is usually not a good idea. Writing the line between \makeatletter and \makeatother just after \usepackage{dot2texi} would be good as well:

\usepackage{tikz}
\usetikzlibrary{shapes,arrows}
\usepackage{dot2texi}
\makeatletter
\@ifundefined{verbatim@out}{\newwrite\verbatim@out}{}
\makeatother