+\newcommand{\glowicon}[1]{\includegraphics[
+ width=\glowiconsize,height=\glowiconsize,keepaspectratio
+]{#1}}
+\newcommand{\ifnotempty}[2]{\expandafter\ifx\expandafter\relax
+ \detokenize{#1}\relax\else #2\fi}
+%s
+''' % (spec.icon_size, spec.layout))