-struct btr_node *btr_new_node(const char *name, struct btr_node *parent,
- btr_command_handler handler, void *context)
+/*
+ (parent, child):
+ (NULL, NULL): new, isolated node.
+ (NULL, c): new node becomes root, c must be old root
+ (p, NULL): new leaf node
+ (p, c): new internal node, ch must be child of p
+
+*/
+struct btr_node *btr_new_node(struct btr_node_description *bnd)