missing rb_tree_subtree_height implemention

[synodriver]

Hi there,
During wrapping this into a python libraty, I found rb_tree_subtree_height missing in rb-tree.c, which appears in the header file.
Did I miss something?

[fragglet]

The red-black tree implementation is incomplete, so that's probably why.

[synodriver]

Thank you for your reply. I'll try to fix that (if I can).

[pradeep2c1]

I have implemented the function for rb_tree_subtree_height for the rb_tree.c file, as described in the header file.
So, can you allow me to create a pull request for the same so that you can look at it; in order to resolve this issue?