public function deleteCategory($id)
    {
        $this->validateId($id);

        $category = $this->getMapper()->find($id);

        if (null === $category) {
            throw new \InvalidArgumentException('No category found for id "' . $id . '"');
        }

        $node = $this->getNestedSetManager()->wrapNode($category);
        $node->delete();

        return $this;
    }