A pointer to a %NULL-terminated array of pointers to #GDBusAnnotationInfo structures or %NULL if there are no annotations.
A pointer to a %NULL-terminated array of pointers to #GDBusArgInfo structures or %NULL if there are no in arguments.
The name of the D-Bus method, e.g. @RequestName.
A pointer to a %NULL-terminated array of pointers to #GDBusArgInfo structures or %NULL if there are no out arguments.
The reference count or -1 if statically allocated.