/**
  * @dataProvider testObjects
  */
 public function testLastIndexOfNonExistingItem(array $testItems)
 {
     $list = new GenericList(TestType::class);
     foreach ($testItems as $testItem) {
         $list->add($testItem);
     }
     $this->assertEquals(-1, $list->lastIndexOf(new TestType('non existing item')));
 }