public function testAddCustomGroupItemFieldWithAttributesFromMethod()
{
$feed = $this->manager->get('article');
$feed->add(new FakeItemInterfaceEntity());
$feed->addItemField(new GroupItemField('categories', new ItemField('category', 'getFeedCategoriesCustom', [], ['getItemKeyAttribute' => 'getItemValueAttribute']), ['getGroupKeyAttribute' => 'getGroupValueAttribute']));
$output = $feed->render('rss');
$this->assertContains('<categories my-group-key-attribute="my-group-value-attribute">', $output);
$this->assertContains('<category my-item-key-attribute="my-item-value-attribute">category 1</category>', $output);
$this->assertContains('<category my-item-key-attribute="my-item-value-attribute">category 2</category>', $output);
$this->assertContains('<category my-item-key-attribute="my-item-value-attribute">category 3</category>', $output);
$this->assertContains('</categories>', $output);
}