public static void clear() {
        logList.clear();
    }
@Test
    void testClear() {
        DubboAppender.doStart();
        DubboAppender appender = new DubboAppender();
        appender.append(event);
        assumeTrue(1 == DubboAppender.logList.size());
        DubboAppender.clear();
        assertThat(DubboAppender.logList, hasSize(0));
    }