docs: protected <T> T execute(InetSocketAddress address, Connection conn, FdfsCommand<T> command) {
          try {
              // 执行交易
              LOGGER.debug("对地址{}发出交易请求{}", address, command.getClass().getSimpleName());
              return command.execute(conn);
          } catch (FdfsException e) {
              throw e;
          } catch (Exception e) {
              LOGGER.error("execute fdfs command error", e);
              throw new RuntimeException("execute fdfs command error", e);
          } finally {
              try {
                  if (null != conn) {
                      //移除pool
                      //pool.invalidateObject(address, conn);
                      pool.returnObject(address, conn);
                  }
              } catch (Exception e) {
                  LOGGER.error("return pooled connection error", e);
              }
          }
      }