Create a tester module in the testnode.py file that contains your function definitions and your code for testing them.

In the testnode.py file, complete the following:

Complete the implementation of the length$()$ function $($not len$).$

This function expects a singly linked structure as an argument.Returns the number of items in the structure.

To test your program run the main$()$ method in the testnode.py file.

Your program's output should look like the following:

$0$: $05$: $5$