Write a method named switchPairs that accepts an ArrayList of strings as a parameter and switches the order of pairs of values in the array.
Your method should swap the order of the first two values, then switch the order of the next two, and so on. For example, if the array stores {"a", "bb", "c", "ddd", "ee", "f", "g"}, then the call of switchPairs(a); should switch the first pair ("a", "bb"), the second pair ("c", "ddd") and the third pair ("ee", "f"), to yield this list:
{"bb", "a", "ddd", "c", "f", "ee", "g"}
If there are an odd number of values, the last element is not moved.
