const char *bus_error_message(const DBusError *error);
typedef int (*BusPropertyCallback)(DBusMessageIter *iter, const char *property, void *data);
-typedef int (*BusPropertySetCallback)(DBusMessageIter *iter, const char *property);
+typedef int (*BusPropertySetCallback)(DBusMessageIter *iter, const char *property, void *data);
typedef struct BusProperty {
const char *property; /* name of the property */