@Override
    public String toString() {
        return "DefaultLoggingFactory{"
                + "level=" + level
                + ", loggers=" + loggers
                + ", appenders=" + appenders
                + '}';
    }
@Test
    void testToStringIsImplemented() {
        assertThat(config.toString()).startsWith(
                "DefaultLoggingFactory{level=INFO, loggers={com.example.app=\"DEBUG\"}, appenders=");
    }