code: public static void decodeLemmasToSpans(final String[] tokens,
        final Span[] preds) {
      for (final Span span : preds) {
        String lemma = decodeShortestEditScript(
            span.getCoveredText(tokens).toLowerCase(), span.getType());
        // System.err.println("-> DEBUG: " + toks[i].toLowerCase() + " " +
        // preds[i] + " " + lemma);
        if (lemma.length() == 0) {
          lemma = "_";
        }
        span.setType(lemma);
      }
    }
docs: Decodes the lemma induced type into the lemma and sets it as value of the
  Span type.
  
  @param tokens
  the tokens in the sentence
  @param preds
  the predicted spans