// Setup ingest factory
        TestIngester ingester = new TestIngester();
        ingestFactory.ingesters.add(ingester);
        ComponentUtil.register(ingestFactory, "ingestFactory");

        // Reinitialize to pick up factory
        indexUpdateCallback.init();

        DataStoreParams paramMap = new DataStoreParams();
        Map<String, Object> dataMap = new HashMap<>();
        dataMap.put("test", "value");

            // but our test implementation always checks system properties
            String value2 = fessConfig.get(testKey);
            // In our test implementation, it will pick up the new value
            assertEquals(newValue, value2);
        } finally {
            // Clean up system property
            System.clearProperty(Constants.FESS_CONFIG_PREFIX + testKey);
        }
    }