code: protected void printError(final String id, final Span references[],
        final Span predictions[], final T referenceSample,
        final T predictedSample, final String[] sentenceTokens) {
      final List<Span> falseNegatives = new ArrayList<Span>();
      final List<Span> falsePositives = new ArrayList<Span>();
  
      findErrors(references, predictions, falseNegatives, falsePositives);
  
      if (falsePositives.size() + falseNegatives.size() > 0) {
  
        if (id != null) {
          this.printStream.println("Id: {" + id + "}");
        }
  
        printSamples(referenceSample, predictedSample);
  
        printErrors(falsePositives, falseNegatives, sentenceTokens);
  
      }
    }
docs: for namefinder, chunker...