code: private void failRemainingBlocks(String[] failedBlockIds, Throwable e) {
      for (String blockId : failedBlockIds) {
        try {
          listener.onBlockFetchFailure(blockId, e);
        } catch (Exception e2) {
          logger.error("Error in block fetch failure callback", e2);
        }
      }
    }
docs: Invokes the "onBlockFetchFailure" callback for every listed block id.