public static String getContent(String content) {
        int index = content.indexOf(WORD_SEPARATOR);
        if (index == -1) {
            throw new IllegalArgumentException("The content does not contain separator!");
        }
        return content.substring(index + 1);
    }
@Test
    void testGetContent() {
        String content = "abc" + Constants.WORD_SEPARATOR + "edf";
        String result = ContentUtils.getContent(content);
        assertEquals("edf", result);
        
        content = "test";
        try {
            ContentUtils.getContent(content);
            fail();
        } catch (IllegalArgumentException e) {
            assertNotNull(e.toString());
        }
        
    }