Java CodeStepByStep || mirror || arrayLisy, collections

Question: Write a method named mirror that accepts an ArrayList of strings as a parameter and produces a mirrored copy of the list as output, with the original values followed by those same values in the opposite order. For example, if an ArrayList variable named list contains the values ["a", "b", "c"], after a call of mirror(list); it should contain ["a", "b", "c", "c", "b", "a"].
You may assume that the list is not null and that no element of the array is null.

Involves: ArrayList, Collections