public function test_iterator_remove_item_2()
 {
     $actual = '';
     $coll = new Collection();
     $coll->addItem('HelloWorld1', 'msg1');
     $coll->addItem('HelloWorld2');
     foreach ($coll as $key => $item) {
         if ($key == 'msg1') {
             $coll->removeItem($key);
             $actual = $item;
         }
     }
     $this->assertEquals('HelloWorld2', $actual);
 }