@Test public void testUnion() { int[] arr1 = new int[]{ 0, 1, 2, 3, 4, 5 }; int[] arr2 = new int[]{ 2, 5, 7, 8 }; int[] inter = ArrayUtils.union(arr1, arr2); assertEquals(8, inter.length); assertEquals(0, inter[0]); assertEquals(1, inter[1]); assertEquals(2, inter[2]); assertEquals(3, inter[3]); assertEquals(4, inter[4]); assertEquals(5, inter[5]); assertEquals(7, inter[6]); assertEquals(8, inter[7]); arr1 = new int[]{}; inter = ArrayUtils.union(arr1, arr2); assertEquals(4, inter.length); assertEquals(2, inter[0]); assertEquals(5, inter[1]); assertEquals(7, inter[2]); assertEquals(8, inter[3]); } }