code: public synchronized void received(SSTableWriter sstable)
      {
          if (done)
              return;
  
          assert cfId.equals(sstable.metadata.cfId);
  
          sstables.add(sstable);
          if (sstables.size() == totalFiles)
          {
              done = true;
              executor.submit(new OnCompletionRunnable(this));
          }
      }
docs: Process received file.
  
  @param sstable SSTable file received.