code: public final Span[] seqToSpans(final String[] tokens) {
      final Span[] annotatedText = this.sequenceLabeler.tag(tokens);
      final List<Span> probSpans = new ArrayList<Span>(
          Arrays.asList(annotatedText));
      return probSpans.toArray(new Span[probSpans.size()]);
    }
docs: Get array of Spans from a list of tokens.
  
  @param tokens
  the sentence tokens
  @return the array of Sequence Spans