@Test
public void testIllegalXor() {

  byte[] arr1 = new byte[34];
  byte[] arr2 = new byte[35];
  boolean thrown = false;
  try {
    ByteArrayHelper.xor(arr1, arr2);
  } catch (IllegalArgumentException e) {
    assertEquals("The byte arrays are not of equal length", e.getMessage());
    thrown = true;
  }
  assertEquals(thrown, true);
}