XBT_PUBLIC(xbt_dynar_t) amok_pm_group_new(const char *group_name);
XBT_PUBLIC(xbt_dynar_t) amok_pm_group_get(gras_socket_t master, const char *group_name);
-XBT_PUBLIC(void) amok_pm_group_join(gras_socket_t master, const char *group_name);
+XBT_PUBLIC(void) amok_pm_group_join(gras_socket_t master, const char *group_name, int rank);
XBT_PUBLIC(void) amok_pm_group_leave(gras_socket_t master, const char *group_name);