void btr_add_output(char *buf, size_t size, struct btr_node *btrn);
bool btr_is_leaf_node(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);