public static String getDefaultNodesPath() {
        return defaultNodesPath;
    }
@Test
    void testGetDefaultNodesPath() {
        String defaultVal = ParamUtil.getDefaultNodesPath();
        assertEquals("serverlist", defaultVal);
        
        String expect = "test";
        ParamUtil.setDefaultNodesPath(expect);
        assertEquals(expect, ParamUtil.getDefaultNodesPath());
    }