code: public synchronized void free(RegularFile file, int count) {
      int remainingCacheSpace = maxCachedBlockCount - blockCache.blockCount();
      if (remainingCacheSpace > 0) {
        file.copyBlocksTo(blockCache, Math.min(count, remainingCacheSpace));
      }
      file.truncateBlocks(file.blockCount() - count);
  
      allocatedBlockCount -= count;
    }
docs: Frees the last {@code count} blocks from the given file.