public static String compareMd5OldResult(List<String> changedGroupKeys) {
        StringBuilder sb = new StringBuilder();
        for (String groupKey : changedGroupKeys) {
            String[] dataIdGroupId = GroupKey2.parseKey(groupKey);
            sb.append(dataIdGroupId[0]);
            sb.append(':');
            sb.append(dataIdGroupId[1]);
            sb.append(';');
        }
        return sb.toString();
    }
@Test
    void testCompareMd5OldResult() {
        
        final MockedStatic<GroupKey2> groupKey2MockedStatic = Mockito.mockStatic(GroupKey2.class);
        
        List<String> changedGroupKeys = new ArrayList<>();
        changedGroupKeys.add("test");
        
        String[] arr = new String[3];
        arr[0] = "test0";
        arr[1] = "test1";
        arr[2] = "test2";
        when(GroupKey2.parseKey(anyString())).thenReturn(arr);
        
        String actualValue = MD5Util.compareMd5OldResult(changedGroupKeys);
        
        assertEquals("test0:test1;", actualValue);
        
        groupKey2MockedStatic.close();
    }