\newcommand{\DeclareDocBookClass}[2][\default]{
\message{^^J\prefix checking for docbook\space\space class \layoutname... }
\@ifundefined{hasdocbook}
\newcommand{\DeclareDocBookClass}[2][\default]{
\message{^^J\prefix checking for docbook\space\space class \layoutname... }
\@ifundefined{hasdocbook}