[Vala] Gee.HashMap<string, int> - uncaught error: No demarshaller registered for type "GeeHashMap"

[Gilles Filippini <gilles filippini free fr>]

Hello,

I'm very new to vala, and while trying to use the Gee.HashMap<string,
int> type to handle a DBus dictionary I encountered the following error:

uncaught error: No demarshaller registered for type "GeeHashMap"

How should I proceed to register a demarshaller?

Thanks in advance,

_Gilles.