\frametitle{Correction}
  \framesubtitle{Ajouter une variable pour activer vnstat}
  \begin{verbatim}
<constraints>
  <check name="valid_enum" target="vnstat_interface">
    <param>['0', '1', '2', '3', '4']</param>
  </check>
  <condition name="disabled_if_in" source="activer_vnstat">
    <param>non</param>
    <target type="family">statistique</target>
    <target type="servicelist">vnstat</target>
    <target type="filelist">vnstat</target>
  </condition>
</constraints>
  \end{verbatim}