public function testIsScoped()
 {
     $category = new Category();
     $this->assertFalse($category->isScoped());
     $category = new ScopedCategory();
     $this->assertTrue($category->isScoped());
     $category = new MultiScopedCategory();
     $this->assertTrue($category->isScoped());
     $category = new OrderedCategory();
     $this->assertFalse($category->isScoped());
 }