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() {

    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() {

    }
  }

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

  public void testSegmentGetAndContains() {

    }
  }

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

  public void testSegmentGetAndContains() {