code: private String createSpan(final String[] tokens, final int from,
        final int to) {
      String tokenSpan = "";
      for (int i = from; i < to; i++) {
        tokenSpan += tokens[i] + " ";
      }
      tokenSpan += tokens[to];
      return tokenSpan;
    }
docs: Create a multi token entry search in the dictionary Map.
  
  @param tokens
  the sentence
  @param from
  the start index
  @param to
  the end index
  @return the string representing the possibly multi token entity