private Throwable createIoException() {
   Throwable exception = null;
   try {
     new FileInputStream(new File(NON_EXISTING_FILE));
     fail("Managed to find a file that shouldn't exist " + NON_EXISTING_FILE);
   } catch (IOException ioe) {
     if (ioe.getStackTrace() == null || ioe.getStackTrace().length == 0) {
       ioe.fillInStackTrace();
     }
     exception = ioe;
   }
   return exception;
 }