code: private static void processSurrogateControlContent(HttpResponse response, boolean keepHeader) {
          if (!response.containsHeader(H_SURROGATE_CONTROL)) {
              return;
          }
  
          if (!keepHeader) {
              response.removeHeaders(H_SURROGATE_CONTROL);
              return;
          }
  
          MoveResponseHeader.moveHeader(response, H_X_NEXT_SURROGATE_CONTROL, H_SURROGATE_CONTROL);
      }
docs: Remove Surrogate-Control header or replace by its new value.
  
  @param response
  backend HTTP response.
  @param keepHeader
  should the Surrogate-Control header be forwarded to the client.