public function testRemove()
 {
     $root = new RootNode();
     $parent_one = $this->createParentNode();
     $parent_one->appendTo($root);
     $one = $this->createNode();
     $one->appendTo($parent_one);
     $two = $this->createNode();
     $two->appendTo($parent_one);
     $parent_two = $this->createParentNode();
     $parent_two->appendTo($root);
     $first = $this->createNode();
     $first->appendTo($parent_two);
     $second = $this->createNode();
     $second->appendTo($parent_two);
     $collection = new NodeCollection([$one, $first], FALSE);
     $collection->remove();
     $this->assertEquals(1, $parent_one->childCount());
     $this->assertEquals(1, $parent_two->childCount());
 }