docs: @Override
      public INDArray getWordVectors(@NonNull Collection<String> labels) {
          int indexes[] = new int[labels.size()];
          int cnt = 0;
          boolean useIndexUnknown = useUnknown && vocab.containsWord(getUNK());
  
          for (String label : labels) {
              if (vocab.containsWord(label)) {
                  indexes[cnt] = vocab.indexOf(label);
              } else
                  indexes[cnt] = useIndexUnknown ? vocab.indexOf(getUNK()) : -1;
              cnt++;
          }
  
          while (ArrayUtils.contains(indexes, -1)) {
              indexes = ArrayUtils.removeElement(indexes, -1);
          }
          if (indexes.length == 0) {
                  return Nd4j.empty(((InMemoryLookupTable)lookupTable).getSyn0().dataType());
          }
  
          INDArray result = Nd4j.pullRows(lookupTable.getWeights(), 1, indexes);
          return result;
      }