auto it = block_map_.lower_bound(begin);
  while (it != block_map_.end() && it->first.first == filename) {
    auto next = std::next(it);
    RemoveBlock(it);
    it = next;
  }
}

void RamFileBlockCache::RemoveBlock(BlockMap::iterator entry) {
  // This signals that the block is removed, and should not be inadvertently
  // reinserted into the cache in UpdateLRU.
  entry->second->timestamp = 0;

  void RemoveFile_Locked(const std::string& filename)
      ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_);

  /// Remove the block `entry` from the block map and LRU list, and update the
  /// cache size accordingly.
  void RemoveBlock(BlockMap::iterator entry) ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_);

  /// The cache pruning thread that removes files with expired blocks.
  std::unique_ptr<TF_Thread, std::function<void(TF_Thread*)>> pruning_thread_;