+struct s_Sys{
+ struct nitni_ref ref; /* real ref struct, must be first */
+};
+typedef struct s_Sys *Sys;
+#define Sys_incr_ref( x ) nitni_global_ref_incr( (struct nitni_ref*)(x) )
+#define Sys_decr_ref( x ) nitni_global_ref_decr( (struct nitni_ref*)(x) )