Gets extra information associated to the proposal. This information will be used to present the user with extra, detailed information about the selected proposal. The returned string must be freed with g_free().
a newly-allocated string containing extra information of @proposal or %NULL if no extra information is associated to @proposal.
See Implementation
Gets extra information associated to the proposal. This information will be used to present the user with extra, detailed information about the selected proposal. The returned string must be freed with g_free().