code: public void handleContextVector(String focusKey,
                                      String secondaryKey,
                                      SparseDoubleVector context) {
          OnlineClustering<SparseDoubleVector> clustering = 
              clusterMap.get(focusKey);
          int contextId = clustering.addVector(context);
          if (reporter != null)
              reporter.assignContextToKey(focusKey, secondaryKey, contextId);
      }
docs: {@inheritDoc}