code: public void setSomePendingWritesAndSave(
        final long atTime,
        final ChangeEvent<BsonDocument> changeEvent
    ) {
      docLock.writeLock().lock();
      try {
        // if we were frozen
        if (isPaused) {
          // unfreeze the document due to the local write
          setPaused(false);
          // and now the unfrozen document is now stale
          setStale(true);
        }
  
        this.lastUncommittedChangeEvent =
            coalesceChangeEvents(this.lastUncommittedChangeEvent, changeEvent);
        this.lastResolution = atTime;
        docsColl.replaceOne(
            getDocFilter(namespace, documentId),
            this);
      } finally {
        docLock.writeLock().unlock();
      }
    }
docs: Sets that there are some pending writes that occurred at a time for an associated
  locally emitted change event. This variant maintains the last version set.
  
  @param atTime      the time at which the write occurred.
  @param changeEvent the description of the write/change.