code: @Override
      public Object jsonToJson(String jsonString) throws IOException {
          return mapper.readValue(jsonString, JsonNode.class);
      }
docs: Converts input JSON string (usually escaped e.g. "{\"a\": \"b\", \"active\": true}" ) to JSON block
  See also-
  - method jsonBlockToJson for unescaped json to json block.
  - method jsonNodeToJson for unescaped json to json block.
  
  @param jsonString - an object of String
  @return a JsonNode object
  @throws IOException - This method might throw IOException