Write a method that accepts an array of integers and returns an array containing the same integers, but grouped by least-significant digit. The grouping must be in order from 0 to 9 of the least-significant digit, but within the group the order of the numbers has not been changed. For example, the array {53,72,18,12,42,83,91,78} becomes {91, 72, 12, 42, 53, 83, 18, 78}. Look at the test data for additional examples. This is easier than it sounds... especially if you don't try to make it super-efficient.