Problem Statement

Write a function to flatten the nesting in an arbitrary list of values. Your program should work on the equivalent of this list: Where the correct result would be the list:

Let's start with the solution:

assert [[1], 2, [[3,4], 5], [[[]]], [[[6]]], 7, 8, []].flatten() == [1, 2, 3, 4, 5, 6, 7, 8]