'tests for get_draft_subtree_roots'

@ddt.data((ONLY_ROOTS, ONLY_ROOTS_URLS), (SOME_TREES, SOME_TREES_ROOTS_URLS))
@ddt.unpack
def test_get_draft_subtree_roots(self, module_nodes, expected_roots_urls):

    subtree_roots_urls = [root.url for root in get_draft_subtree_roots(module_nodes)]
    self.assertEqual(set(subtree_roots_urls), set(expected_roots_urls))
