code: private void findErrors(final Span references[], final Span predictions[],
        final List<Span> falseNegatives, final List<Span> falsePositives) {
  
      falseNegatives.addAll(Arrays.asList(references));
      falsePositives.addAll(Arrays.asList(predictions));
  
      for (final Span referenceName : references) {
  
        for (final Span prediction : predictions) {
          if (referenceName.equals(prediction)) {
            // got it, remove from fn and fp
            falseNegatives.remove(referenceName);
            falsePositives.remove(prediction);
          }
        }
      }
    }
docs: Outputs falseNegatives and falsePositives spans from the references and
  predictions list.
  
  @param references
  @param predictions
  @param falseNegatives
  [out] the false negatives list
  @param falsePositives
  [out] the false positives list