code: public Recommender buildRecommender(final DataModel dataModel, final String recType)
              throws RecommenderException {
          return buildRecommender(dataModel, recType, null, DEFAULT_N, NOFACTORS, NOITER, null);
      }
docs: CF recommender with default parameters.
  
  @param dataModel the data model
  @param recType the recommender type (as Mahout class)
  @return the recommender
  @throws RecommenderException see {@link #buildRecommender(org.apache.mahout.cf.taste.model.DataModel, java.lang.String, java.lang.String, int, int, int, java.lang.String)}