public boolean isExist(final String key) {
        try {
            return null != client.checkExists().forPath(key);
        } catch (Exception e) {
            throw new ShenyuException(e);
        }
    }
@Test
    void isExist() throws Exception {
        assertThrows(ShenyuException.class, () -> client.isExist("/test"));
        ExistsBuilderImpl existsBuilder = mock(ExistsBuilderImpl.class);
        when(curatorFramework.checkExists()).thenReturn(existsBuilder);
        when(existsBuilder.forPath(anyString())).thenReturn(new Stat());
        boolean exist = client.isExist("/test");
        assertTrue(exist);
    }