code: private void printErrors(final List<Span> falsePositives,
        final List<Span> falseNegatives, final String doc) {
      this.printStream.println("False positives: {");
      for (final Span span : falsePositives) {
        this.printStream.println(span.getCoveredText(doc));
      }
      this.printStream.println("} False negatives: {");
      for (final Span span : falseNegatives) {
        this.printStream.println(span.getCoveredText(doc));
      }
      this.printStream.println("}\n");
    }
docs: Auxiliary method to print span errors
  
  @param falsePositives
  false positives span
  @param falseNegatives
  false negative span
  @param doc
  the document text