code: public float[] predict(FVec feat, boolean output_margin, int ntree_limit) {
          float[] preds = predictRaw(feat, ntree_limit);
          if (! output_margin) {
              preds = obj.predTransform(preds);
          }
          return preds;
      }
docs: Generates predictions for given feature vector.
  
  @param feat          feature vector
  @param output_margin whether to only predict margin value instead of transformed prediction
  @param ntree_limit   limit the number of trees used in prediction
  @return prediction values