Iterator<String> cycle = Iterators.cycle("a", "b");
    assertTrue(cycle.hasNext());
    assertThrows(IllegalStateException.class, () -> cycle.remove());
  }

  public void testCycleRemoveSameElementTwice() {
    Iterator<String> cycle = Iterators.cycle("a", "b");
    cycle.next();
    cycle.remove();
    assertThrows(IllegalStateException.class, () -> cycle.remove());
  }