public boolean isEmpty() {
      return head.getNextInWriteQueue() == head;
    }

    @Override
    public int size() {
      int size = 0;
      for (ReferenceEntry<K, V> e = head.getNextInWriteQueue();
          e != head;
          e = e.getNextInWriteQueue()) {
        size++;
      }
      return size;
    }

    @Override
    public void clear() {

  /** Sets the entry write time in ns. */
  @SuppressWarnings("GoodTime") // b/122668874
  void setWriteTime(long time);

  /** Returns the next entry in the write queue. */
  ReferenceEntry<K, V> getNextInWriteQueue();

  /** Sets the next entry in the write queue. */
  void setNextInWriteQueue(ReferenceEntry<K, V> next);

  /** Returns the previous entry in the write queue. */

    }
  }

  private static <K, V> void assertConnected(
      LocalCache<K, V> map, ReferenceEntry<K, V> one, ReferenceEntry<K, V> two) {
    if (map.usesWriteQueue()) {
      assertSame(two, one.getNextInWriteQueue());
    }
    if (map.usesAccessQueue()) {
      assertSame(two, one.getNextInAccessQueue());
    }
  }

  public void testSegmentGetAndContains() {
    FakeTicker ticker = new FakeTicker();

    }
  }

  private static <K, V> void assertConnected(
      LocalCache<K, V> map, ReferenceEntry<K, V> one, ReferenceEntry<K, V> two) {
    if (map.usesWriteQueue()) {
      assertSame(two, one.getNextInWriteQueue());
    }
    if (map.usesAccessQueue()) {
      assertSame(two, one.getNextInAccessQueue());
    }
  }

  public void testSegmentGetAndContains() {
    FakeTicker ticker = new FakeTicker();