@Test
public void testWriteJsonToJavaObject(){

        String jsonString = "[\"hdfs\",\"hive\",\"knox\"]";
        Set<String> expectedSet = new HashSet<String>();
        expectedSet.add("hive");
        expectedSet.add("hdfs");
        expectedSet.add("knox");
        Set<String> testSet = new HashSet<>();
        Set<String> actualSet = jsonUtil.writeJsonToJavaObject(jsonString, testSet.getClass());
        Assert.assertEquals(expectedSet, actualSet);
}