@Test public void shouldConcatenateArraysIfThereArentArrayCollisions() {

  int a1[] = { 1, 2, 3, 4, 5 };
  int a2[] = { 7, 8, 9 };
  int[] result = mergeSortedArrays.merge(a1, a2);
  int[] expectedArray = { 1, 2, 3, 4, 5, 7, 8, 9 };
  assertArrayEquals(expectedArray, result);
}