public String simple() {
    final StringBuilder buf = new StringBuilder("(");
    for (Ord<Pair<String, Object>> ord : Ord.zip(values)) {
      if (ord.i > 0) {
        buf.append(", ");
      }
      buf.append(ord.e.left).append("=[").append(ord.e.right).append("]");
    }
    buf.append(")");
    return buf.toString();
  }
Converts the collected terms and values to a string. Does not write to
the parent writer.
ql/src/java/org/apache/hadoop/hive/ql/optimizer/calcite/RelWriterImplCopy.java