synonymFile.insert(synonymItem1);
         final PagingList<SynonymItem> itemList2 = synonymFile.selectList(0, 20);
         assertEquals(6, itemList2.size());
         assertEquals("z1", itemList2.get(5).getInputs()[0]);
         assertEquals("z2", itemList2.get(5).getInputs()[1]);
         assertEquals("Z1", itemList2.get(5).getOutputs()[0]);

        responseDataMap.put("z", "Z0");
        responseDataMap.put("z.overwrite", "Z1");

        indexUpdateCallback.mergeResponseData(dataMap, responseDataMap);

        assertFalse(dataMap.containsKey("z.overwrite"));
        assertEquals(1, dataMap.size());
        assertEquals("Z1", dataMap.get("z"));
    }