function testShouldNotRedirectIfRedirectUrlEmpty()
 {
     $r = $this->response('sale3d_async.xml');
     $r['redirect_url'] = '';
     $t = new Transaction($r);
     $this->assertFalse($t->shouldRedirect());
     $this->assertEqual('', $t->redirect_url);
     $this->assertTrue($t->isPendingAsync());
     $this->assertPattern('|^[a-f0-9]{32}$|', $t->unique_id);
 }