[get.https.window.html]
  expected:
    if os == "win": [OK, TIMEOUT]
  [BackgroundFetchManager.get() does not require an activated worker]
    expected:
      if os == "win": [FAIL, TIMEOUT]
      FAIL

  [Getting non-existing registrations yields `undefined`]
    expected:
      if os == "win": [FAIL, NOTRUN]
      FAIL

  [Getting an existing registration has the expected values]
    expected:
      if os == "win": [FAIL, NOTRUN]
      FAIL