"""This problem was asked by Airbnb.

Given an array of integers, return the largest range, inclusive, 
of integers that are all included in the array.

For example, given the array [9, 6, 1, 3, 8, 10, 12, 11], 
return (8, 12) since 8, 9, 10, 11, and 12 are all in the array."""