@Test
public void doubleRing_ioExceptionInBackup() throws Exception {

    final IOException exception = new IOException();
    new Expectations() {
        {
            doubleRing.backup();
            result = exception;
            doubleRing.restore();
        }
    };
    try {
        resource.doubleRing();
        fail("Excepted RuntimeException");
    } catch (RuntimeException e) {
        assertEquals(exception, e.getCause());
    }
}