docs: @Override
      public Pair<List<String>, AtomicLong> call(List<String> lstOfWords) throws Exception {
          List<String> stops = stopWords.getValue();
          Counter<String> counter = new Counter<>();
  
          for (String w : lstOfWords) {
              if (w.isEmpty())
                  continue;
  
              if (!stops.isEmpty()) {
                  if (stops.contains(w)) {
                      counter.incrementCount("STOP", 1.0f);
                  } else {
                      counter.incrementCount(w, 1.0f);
                  }
              } else {
                  counter.incrementCount(w, 1.0f);
              }
          }
          wordFreqAcc.add(counter);
          AtomicLong lstOfWordsSize = new AtomicLong(lstOfWords.size());
          return new Pair<>(lstOfWords, lstOfWordsSize);
      }