docs: public void advanceLastDiscoveredShardOfStream(String stream, String shardId) {
  		String lastSeenShardIdOfStream = this.subscribedStreamsToLastDiscoveredShardIds.get(stream);
  
  		// the update is valid only if the given shard id is greater
  		// than the previous last seen shard id of the stream
  		if (lastSeenShardIdOfStream == null) {
  			// if not previously set, simply put as the last seen shard id
  			this.subscribedStreamsToLastDiscoveredShardIds.put(stream, shardId);
  		} else if (shouldAdvanceLastDiscoveredShardId(shardId, lastSeenShardIdOfStream)) {
  			this.subscribedStreamsToLastDiscoveredShardIds.put(stream, shardId);
  		}
  	}