presto-postgresql/src/main/java/io/prestosql/plugin/postgresql/PostgreSqlClient.java/PostgreSqlClient/timestampWithTimeZoneColumnMapping
class PostgreSqlClient:    private static ColumnMapping timestampWithTimeZoneColumnMapping()
    {
        return ColumnMapping.longMapping(
                TIMESTAMP_WITH_TIME_ZONE,
                (resultSet, columnIndex) -> {
                    // PostgreSQL does not store zone information in "timestamp with time zone" data type
                    long millisUtc = resultSet.getTimestamp(columnIndex).getTime();
                    return packDateTimeWithZone(millisUtc, UTC_KEY);
                },
                timestampWithTimeZoneWriteFunction());
    }