code: public static Map<String, Object> parseJsonString(String json) throws IOException {
          ObjectMapper mapper = new ObjectMapper();
          TypeReference<HashMap<String, Object>> typeRef = new TypeReference<HashMap<String, Object>>() {
          };
          return mapper.readValue(json, typeRef);
      }
docs: Convenience function for parsing JSON strings.
  
  @param json String containing valid JSON
  @return Nested (key,value) map of arbitrary depth
  @throws IOException IO exception