code: public void addExStrFeats(double weight, Object xObj, Object yObj, List<String>[] fvStrs) {
          FeatureVector[] fvs = new FeatureVector[fvStrs.length];
          for (int i=0; i<fvs.length; i++) {
              fvs[i] = new FeatureVector();
              for (String featName : fvStrs[i]) {
                  fvs[i].add(featAlphabet.lookupIndex(featName), 1);
              }
          }
          addEx(weight, xObj, yObj, fvs);
      }
docs: Adds a new log-linear model instance.
  
  @param weight The weight of this example.
  @param x The observation, x.
  @param y The prediction, y.
  @param fvs The binary features on the observations, x, for all possible labels, y'. Indexed by y'.