Can I test Extended Query in core test framework - Mailing list pgsql-hackers

PreparedStatement preparedStatement  = conn.prepareStatement("select * from bigtable");
preparedStatement.setFetchSize(4);
ResultSet rs = preparedStatement.executeQuery();
while(rs.next())
{
    System.out.println(rs.getInt(1));
    // conn.commit();
    conn.rollback();
}