preferred example

$this->assertNotSame($view1, $view2);
        $this->assertEquals(new ChoiceListView(), $view1);
        $this->assertEquals(new ChoiceListView(), $view2);
    }

    public function testCreateViewSamePreferredChoicesUseCache()
    {
        $preferred = ['a'];
        $type = new FormType();
        $list = new ArrayChoiceList([]);
        $view1 = $this->factory->createView($list, ChoiceList::preferred($type, $preferred));
        $view2 = $this->factory->createView($list, ChoiceList::preferred($type, ['a']));

        $this->assertSame($view1, $view2);
        $this->assertEquals(new ChoiceListView(), $view1);
        $this->assertEquals(new ChoiceListView(), $view2);
    }

    public function testCreateViewDifferentPreferredChoices()
    {
        $preferred1 = ['a'];
        $preferred2 = ['b'];