code: private void parseLine(final String line, final DataModelIF<Long, Long> dataset) {
          String[] toks = line.split("\t");
          // user
          long userId = Long.parseLong(toks[USER_TOK]);
          // item
          long itemId = Long.parseLong(toks[ITEM_TOK]);
          // preference
          double preference = Double.parseDouble(toks[RATING_TOK]);
          //////
          // update information
          //////
          dataset.addPreference(userId, itemId, preference);
          // no timestamp info
      }
docs: A method that parses a line from the file.
  
  @param line the line to be parsed
  @param dataset the dataset where the information parsed from the line
  will be stored into.