new_contents: import pytest
  
  @pytest.mark.parametrize("name, user, group, mode, contains", [
    ("/etc/apt/sources.list.d/docker.list", "root", "root", "0644", "deb https://apt.dockerproject.org/repo"),
    ("/tmp/docker-lab/", "root", "root", "0755", "null"),
    ("/tmp/CV/", "root", "root", "0755", "null"),
    ("/usr/local/bin/docker-clean.sh", "root", "root", "0755", "/usr/bin/docker"),
  ])
  
  def test_files(File, name, user, group, mode, contains):
    assert File(name).exists
    assert File(name).user == user
    assert File(name).group == group
    assert oct(File(name).mode) == mode
    if File(name).is_directory is not True:
      assert File(name).contains(contains)
    else:
      assert File(name).is_directory
subject: Add test for files