typedef int (*btr_command_handler)(struct btr_node *btrn,
const char *command, char **result);
-struct btr_node *btr_new_node(char *name, struct btr_node *parent,
+struct btr_node *btr_new_node(const char *name, struct btr_node *parent,
btr_command_handler handler, void *context);
void btr_del_node(struct btr_node *btrn);
void btr_add_output(char *buf, size_t size, struct btr_node *btrn);
int btr_splice_out_node(struct btr_node *btrn);
void btr_pushdown(struct btr_node *btrn);
void *btr_context(struct btr_node *btrn);
+int btr_merge(struct btr_node *btrn);