*
   * <p>Note that the cache <b>may evict an entry before this limit is exceeded</b>. For example, in
   * the current implementation, when {@code concurrencyLevel} is greater than {@code 1}, each
   * resulting segment inside the cache <i>independently</i> limits its own size to approximately
   * {@code maximumSize / concurrencyLevel}.
   *
   * <p>When eviction is necessary, the cache evicts entries that are less likely to be used again.

   * (unless they were already returned).
   *
   * The iterator supports [MutableIterator.remove]. Removing a URL from the iterator evicts the
   * corresponding response from the cache. Use this to evict selected responses.
   */
  @Throws(IOException::class)
  fun urls(): MutableIterator<String> {
    return object : MutableIterator<String> {

    assertThat(get(url).body.string()).isEqualTo("a")

    // The URL will remain available if hasNext() returned true...
    val i = cache.urls()
    assertThat(i.hasNext()).isTrue()

    // ...so even when we evict the element, we still get something back.
    cache.evictAll()
    assertThat(i.next()).isEqualTo(url.toString())

    // Remove does nothing. But most importantly, it doesn't throw!
    i.remove()
  }

                }
              });
    }

    threadPool.shutdown();
    threadPool.awaitTermination(300, SECONDS);

    // Since we're not doing any more cache operations, and the cache only expires/evicts when doing
    // other operations, the cache and the removal queue won't change from this point on.

    // Verify that each received removal notification was valid

                }
              });
    }

    threadPool.shutdown();
    threadPool.awaitTermination(300, SECONDS);

    // Since we're not doing any more cache operations, and the cache only expires/evicts when doing
    // other operations, the cache and the removal queue won't change from this point on.

    // Verify that each received removal notification was valid