def run_nested_groups():
  """Run the nested groups example.

  This example shows a PhaseGroup in a PhaseGroup.  No phase is terminal, so all
  are run in the order;
    main_phase
    inner_main_phase
    inner_teardown_phase
    teardown_phase
  """
  test = htf.Test(
      htf.PhaseGroup(
          main=[
              main_phase,
              htf.PhaseGroup.with_teardown(inner_teardown_phase)(
                  inner_main_phase),
          ],
          teardown=[teardown_phase]
      )
  )
  test.execute()
Run the nested groups example.

  This example shows a PhaseGroup in a PhaseGroup.  No phase is terminal, so all
  are run in the order;
    main_phase
    inner_main_phase
    inner_teardown_phase
    teardown_phase