SimpleTest for "Subquery handling" fails

Hello.

i'm using
- Drupal 6.15,
- ApacheSolr Search 6.x-1.0-rc4
- SimpleTest 6.x-2.10.

After enabling the SimpleTest module i tried to run the
"Subquery handling Tests for subqueries." from the ApacheSolr suite of tests.

However it fails giving a message

"Call to a member function add_subquery() on a non-object" - PHP Fatal error - solr_base_subquery.test - line 20 - Unknown
On seeing the code

      1 <?php
      2 // $Id: solr_base_subquery.test,v 1.1.2.4 2008/12/18 09:47:38 jacobsingh Exp $
      3 
      4 class DrupalSolrSubQueryTests extends DrupalWebTestCase {
      5   function getInfo() {
      6     return array('name' => 'Subquery handling',
      7       'description' => 'Tests for subqueries.',
      8       'group' => 'ApacheSolr');
      9   }
     10 
     11   function setUp() {
     12     parent::setUp('search', 'apachesolr');
     13   }
     14 
     15   function testSubQueriesQuery() {
     16     $query1 = apachesolr_drupal_query('foo', '', '', TRUE);
     17     $query2 = apachesolr_drupal_query('bar');
     18     $query3 = apachesolr_drupal_query('baz');
     19 
     20     $query1->add_subquery($query2);

it seems $query1 on line 16 was not created

Regards.

Yashesh