code: public static DateTime calciteTimestampToJoda(final long timestamp, final DateTimeZone timeZone)
    {
      return new DateTime(timestamp, DateTimeZone.UTC).withZoneRetainFields(timeZone);
    }
docs: The inverse of {@link #jodaToCalciteTimestamp(DateTime, DateTimeZone)}.
  
  @param timestamp Calcite style timestamp
  @param timeZone  session time zone
  
  @return joda timestamp, with time zone set to the session time zone