int wng_open(struct writer_node_group *g);
void wng_close(struct writer_node_group *g);
struct writer_node_group *wng_new(unsigned num_writers);
-void wng_destroy(struct writer_node_group *g);
+void wng_unregister(struct writer_node_group *g);
void init_supported_writers(void);
void *check_writer_arg(char *wa, int *writer_num);
struct writer_node_group *setup_default_wng(void);