We now wish to create a new merge operation, called merge3, to merge three independently sorted arrays into one fully sorted array. In Java, write this new merge3 operation by making use of calls to the original merge in part a. It takes in three independently sorted arrays of type int and returns a single array containing all the elements of the input arrays fully sorted. It must run in O(n) time, where n is the total number of elements across all three arrays. Your method signature should be: int[] merge3(int[] a, int