@Test
public void testConcat() {

  final StackTraceElement[] left = new Throwable().getStackTrace();
  final StackTraceElement[] right = new Throwable().getStackTrace();
  final StackTraceElement[] expected = Arrays.copyOf(left, left.length + right.length);
  System.arraycopy(right, 0, expected, left.length, right.length);
  assertTrue(Arrays.equals(expected, ExceptionUtils.concat(left, right)));
}