Cannot easily capture logs for the DEBUG level

public class AllLogRuleDebugLevelTest
{
    public static final Logger LOGGER = LoggerFactory.getLogger(AllLogRuleDebugLevelTest.class);

    @Rule
    public AllLogRule logRule = new AllLogRule(LogLevel.DEBUG);

    @Test
    public void staticLogger()
    {
        LOGGER.debug("test1");
        assertEquals("test1", this.logRule.getMessage(0));
    }
}