code: def test_grouped_size_3_groups_6_elements():
      actual = list(grouped(3, ["abc", "def", "ghi", "jkl", "mno", ""]))
      expected = [["abc", "def", "ghi"], ["jkl", "mno", ""]]
      assert actual == expected
  
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 19 for calling a global function with example usage: test_grouped_size_3_groups_6_elements() without return types