code: public static String compose(String op, Class<? extends InputFormat> inf,
        String... path) {
      final String infname = inf.getName();
      StringBuffer ret = new StringBuffer(op + '(');
      for (String p : path) {
        compose(infname, p, ret);
        ret.append(',');
      }
      ret.setCharAt(ret.length() - 1, ')');
      return ret.toString();
    }
docs: Convenience method for constructing composite formats.
  Given operation (op), Object class (inf), set of paths (p) return:
  {@code <op>(tbl(<inf>,<p1>),tbl(<inf>,<p2>),...,tbl(<inf>,<pn>)) }