protected void featurize(WordAlignment sent) {
   int fsize = sent.f().size();
   int esize = sent.e().size();
   // Features are extracted only once all phrases for a given
   // sentence pair are in memory
   for (AbstractFeatureExtractor e : extractors) {
     for (AlignmentTemplateInstance alTemp : alGrid.getAlTemps()) {
       e.featurizePhrase(alTemp, alGrid);
       if (PRINT_PHRASAL_GRID && fsize < PRINT_GRID_MAX_LEN && esize < PRINT_GRID_MAX_LEN)
         alGrid.printAlTempInGrid("phrase id: " + alTemp.getKey(), alTemp, System.err);
     }
   }
 }