code: public <T> T readToJson(Type type) {
          try {
              return JsonLookup.getInstance().lookup().unmarshal(body(), getCharset(), type);
          } catch (IOException e) {
              throw new RequestsException(e);
          } finally {
              close();
          }
      }
docs: Deserialize response content as json
  
  @return null if json value is null or empty