long lastAccessTime = 0;
      long lastWriteTime = 0;
      for (ReferenceEntry<K, V> e : segment.recencyQueue) {
        long accessTime = e.getAccessTime();
        assertTrue(accessTime >= lastAccessTime);
        lastAccessTime = accessTime;
        long writeTime = e.getWriteTime();
        assertTrue(writeTime >= lastWriteTime);
        lastWriteTime = writeTime;
      }

      long lastAccessTime = 0;
      long lastWriteTime = 0;
      for (ReferenceEntry<K, V> e : segment.recencyQueue) {
        long accessTime = e.getAccessTime();
        assertTrue(accessTime >= lastAccessTime);
        lastAccessTime = accessTime;
        long writeTime = e.getWriteTime();
        assertTrue(writeTime >= lastWriteTime);
        lastWriteTime = writeTime;
      }

    }

    // The code below is exactly the same for each access entry type.

    volatile long accessTime = Long.MAX_VALUE;

    @Override
    public long getAccessTime() {
      return accessTime;
    }

    @Override
    public void setAccessTime(long time) {
      this.accessTime = time;
    }

    // Guarded By Segment.this
    @Weak ReferenceEntry<K, V> nextAccess = nullEntry();