code: public void notifyQueryTokenReceived(QueryToken queryToken, List<String> buckets) {
          synchronized (mLock) {
              Set<String> currentBuckets = mWaitingForResults.get(queryToken);
              if (currentBuckets == null) {
                  currentBuckets = new HashSet<>();
              }
              currentBuckets.addAll(buckets);
              mWaitingForResults.put(queryToken, currentBuckets);
          }
      }
docs: Method to notify the adapter that a new {@link QueryToken} has been received and that
  suggestions will be added to the adapter once generated.
  
  @param queryToken the {@link QueryToken} that has been received
  @param buckets    a list of string dictating which buckets the future query results will go into