code: private void addEntitySelector(Map<String, String> requestParameters, StringBuilder uri) {
          if (StringUtils.hasText(requestParameters.get(RequestElements.REQ_PARAM_ENTITY_SELECTOR))) {
              uri.append("/").append(requestParameters.get(RequestElements.REQ_PARAM_ENTITY_SELECTOR));
          }
      }
docs: adding additional selector in the URI, which is required for READ operation
  Main purpose is to select or modify requested resource with well-defined keyword
  @param requestParameters
  @param uri