node->prev = node->next = node->parent = NULL;
tree->head = tree->tail = tree->root = node;
}
void avl_insert_before(avl_tree_t *tree, avl_node_t *before,
node->prev = node->next = node->parent = NULL;
tree->head = tree->tail = tree->root = node;
}
void avl_insert_before(avl_tree_t *tree, avl_node_t *before,