Another l3keys puzzle : the following code

\documentclass{minimal}
\usepackage{expl3}
\begin{document}
\ExplSyntaxOn
\keys_define:nn {module} {
  a .default:n = Alice ,
  a .code:n = Hello #1 ,
}
\keys_set:nn {module} {a}
\ExplSyntaxOff
\end{document}

produces "Hello ", but if I swap the "default:n" and "code:n" line, I
get "Hello Alice".

The example from the documentation (latex3-source.pdf) also puts the
"default:n" line last. Is that mandatory ?

-- 
Rémy.