code: private static RuntimeException getCause(final InvocationTargetException e) {
      final Throwable cause = e.getCause();
      if (cause instanceof RuntimeException) {
        throw (RuntimeException) cause;
      } else {
        throw new IllegalStateException(e.getCause());
      }
    }
docs: Get the root cause of the Exception
  
  @param e The Exception
  @return The root cause of the Exception