+bool btr_no_children(struct btr_node *btrn);
+size_t btr_bytes_pending(struct btr_node *btrn);
+size_t btr_get_input_queue_size(struct btr_node *btrn);
+bool btr_no_parent(struct btr_node *btrn);
+size_t btr_next_buffer(struct btr_node *btrn, char **bufp);
+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);
+void btr_splice_out_node(struct btr_node *btrn);
+void btr_pushdown(struct btr_node *btrn);
+void *btr_context(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);
+int btr_node_status(struct btr_node *btrn, size_t min_iqs,
+ enum btr_node_type type);
+void btr_get_node_start(struct btr_node *btrn, struct timeval *tv);