/**
  * Test that DataList::relation works with PolymorphicHasManyList
  */
 public function testFilterRelation()
 {
     // Check that expected teams exist
     $list = DataObjectTest_Team::get();
     $this->assertEquals(array('Subteam 1', 'Subteam 2', 'Subteam 3', 'Team 1', 'Team 2', 'Team 3'), $list->sort('Title')->column('Title'));
     // Check that fan list exists
     $fans = $list->relation('Fans');
     $this->assertEquals(array('Damian', 'Mitch', 'Richard'), $fans->sort('Name')->column('Name'));
     // Modify list of fans and retest
     $team1 = $this->objFromFixture('DataObjectTest_Team', 'team1');
     $subteam1 = $this->objFromFixture('DataObjectTest_SubTeam', 'subteam1');
     $newFan1 = DataObjectTest_Fan::create();
     $newFan1->Name = 'Bobby';
     $newFan1->write();
     $newFan2 = DataObjectTest_Fan::create();
     $newFan2->Name = 'Mindy';
     $newFan2->write();
     $team1->Fans()->add($newFan1);
     $subteam1->Fans()->add($newFan2);
     $fans = DataObjectTest_Team::get()->relation('Fans');
     $this->assertEquals(array('Bobby', 'Damian', 'Richard'), $team1->Fans()->sort('Name')->column('Name'));
     $this->assertEquals(array('Mindy', 'Mitch'), $subteam1->Fans()->sort('Name')->column('Name'));
     $this->assertEquals(array('Bobby', 'Damian', 'Mindy', 'Mitch', 'Richard'), $fans->sort('Name')->column('Name'));
 }