(Combine two lists) Write a method that returns the union of two array lists of integers using the following header: public static ArrayList union(  ArrayList list1, ArrayList list2) For example, the...

(Combine two lists) Write a method that returns the union of two array lists of integers using the following header:

public static ArrayList union(

 ArrayList list1, ArrayList list2)

For example, the addition of two array lists {2, 3, 1, 5} and {3, 4, 6} is {2, 3, 1, 5, 3, 4, 6}. Write a test program that prompts the user to enter two lists, each with five integers, and displays their union. The numbers are separated by exactly one space. Here is a sample run: