void btr_consume(struct btr_node *btrn, size_t numbytes);
int btr_exec(struct btr_node *btrn, const char *command, char **value_result);
int btr_exec_up(struct btr_node *btrn, const char *command, char **value_result);
-int btr_splice_out_node(struct btr_node *btrn);
+void 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);
+void btr_merge(struct btr_node *btrn, size_t dest_size);
+bool btr_eof(struct btr_node *btrn);
+void btr_log_tree(struct btr_node *btrn, int loglevel);
+int btr_pushdown_one(struct btr_node *btrn);
+bool btr_inplace_ok(struct btr_node *btrn);