Iterator<T> iterator = unmodifiableList(list).iterator();
        return Iterators.peekingIterator(iterator);
      }
    }.test();
  }

  public void testPeekingIteratorBehavesLikeIteratorOnEmptyIterable() {
    actsLikeIteratorHelper(emptyList());
  }

  public void testPeekingIteratorBehavesLikeIteratorOnSingletonIterable() {
    actsLikeIteratorHelper(singletonList(new Object()));
  }