### Question:
PolicyClientImpl implements PolicyClient { protected Config getConfigFromStringJson(String configJson) throws JsonParseException, JsonMappingException, IOException { String unescapedJson = configJson.replaceAll("\\\\", ""); mapper.configure(SerializationFeature.WRAP_ROOT_VALUE, false); mapper.configure(DeserializationFeature.UNWRAP_ROOT_VALUE, false); return mapper.readValue(unescapedJson, Config.class); } PolicyClientImpl(); PolicyDecision getDecision(String serviceType, String vnfType, String bbID, String workStep,
            String errorCode); DictionaryData getAllowedTreatments(String bbID, String workStep); @Override Config getConfigWithPolicyName(String policyName);  }### Answer:
@Test public void getConfigFromStringJsonTest() throws IOException { PolicyClientImpl client = new PolicyClientImpl(); ObjectMapper mapper = new ObjectMapper(); mapper.configure(SerializationFeature.WRAP_ROOT_VALUE, false); mapper.configure(DeserializationFeature.UNWRAP_ROOT_VALUE, false); Config expected = mapper.readValue(new File(RESOURCE_PATH + "configJson.json"), Config.class); PolicyConfig[] returnedPolicyConfigList = mapper.readValue(new File(RESOURCE_PATH + "policyConfig.json"), PolicyConfig[].class); String configJson = returnedPolicyConfigList[0].getConfig(); Config actual = client.getConfigFromStringJson(configJson); assertThat(actual, sameBeanAs(expected)); }