public static function only_download_test_files(&$test_profiles, $to_dir = null)
 {
     // Setup the install manager and add the tests
     $test_install_manager = new pts_test_install_manager();
     foreach ($test_profiles as &$test_profile) {
         if ($test_install_manager->add_test_profile($test_profile) != false) {
             pts_client::$display->generic_sub_heading('To Download Files: ' . $test_profile->get_identifier());
         }
     }
     if ($test_install_manager->tests_to_install_count() == 0) {
         return true;
     }
     // Let the pts_test_install_manager make some estimations, etc...
     $test_install_manager->generate_download_file_lists();
     $test_install_manager->check_download_caches_for_files();
     // Begin the download process
     while (($test_install_request = $test_install_manager->next_in_install_queue()) != false) {
         //pts_client::$display->test_install_start($test_install_request->test_profile->get_identifier());
         pts_test_installer::download_test_files($test_install_request, $to_dir);
     }
 }