docs: public void setRequest(ServletRequest request) {
          if (request != null) {
              if (logger.isDebugEnabled()) {
                  logger.debug(String.format("set request: %s", request));
              }
              this.threadLocalRequests.set((HttpServletRequest) request);
          } else {
              //if null, remove from threadLocalRequests
              // @see WindowTask#run 's finally
              if (logger.isDebugEnabled()) {
                  HttpServletRequest tmpRequest = this.threadLocalRequests.get();
                  logger.debug(String.format("remove request: %s", tmpRequest));
              }
              this.threadLocalRequests.remove();
          }
      }