code: def test_url_scheme():
      assert url_scheme("https://hail.is/path/to") == "https"
      assert url_scheme("/path/to") == ""
  
imports: from hailtop.utils import partition, url_basename, url_join, url_scheme, url_and_params, parse_docker_image_reference, grouped
  from hailtop.utils.utils import digits_needed, unzip, filter_none, flatten
label_desc: Use image node_id 8 for calling a global function with example usage: test_url_scheme() without return types