code: private String punct(Parse punct, int i) {
      StringBuffer feat = new StringBuffer(5);
      feat.append(i).append("=");
      feat.append(punct.getType());
      return (feat.toString());
    }
docs: Creates punctuation feature for the specified punctuation at the specfied index.
  @param punct The punctuation which is in context.
  @param i The index of the punctuation with relative to the parse.
  @return Punctuation feature for the specified parse and the specified punctuation at the specfied index.