Extend your program in lua to also do the following:

Opens a text file called graph.txt which contains values to be inserted in an AVL$-$tree data structure in the following format

Value $($on a single line$)$

For example the file defining the tree above contains the following:

A

E

I

$0$

$u$

B

C

D

You may assume that values are single letters and that there are no duplicates

Add support for the following two commands to your system:

Command: showchildren

Parameters: $1$ letter

Command: insert

Parameters: $1$ letter