code: public static Dictionary buildDictionary(final ObjectStream<Parse> data,
        final HeadRules rules, final int cutoff) throws IOException {
  
      final TrainingParameters params = new TrainingParameters();
      params.put("dict", TrainingParameters.CUTOFF_PARAM,
          Integer.toString(cutoff));
  
      return buildDictionary(data, rules, params);
    }
docs: Creates a n-gram dictionary from the specified data stream using the
  specified head rule and specified cut-off.
  
  @param data
  The data stream of parses.
  @param rules
  The head rules for the parses.
  @param cutoff
  The minimum number of entries required for the n-gram to be saved
  as part of the dictionary.
  @throws IOException
  if io problems
  @return A dictionary object.