@Test
public void getWindow_setsTag() {

  Object tag = new Object();
  SinglePeriodTimeline timeline =
      new SinglePeriodTimeline(
          /* durationUs= */ C.TIME_UNSET,
          /* isSeekable= */ false,
          /* isDynamic= */ false,
          /* isLive= */ false,
          /* manifest= */ null,
          tag);
  assertThat(timeline.getWindow(/* windowIndex= */ 0, window).tag).isEqualTo(tag);
}