String not = new String("a");

    Interner<String> pool = Interners.newStrongInterner();
    assertThat(pool.intern(canonical)).isSameInstanceAs(canonical);
    assertThat(pool.intern(not)).isSameInstanceAs(canonical);
  }

  public void testStrong_null() {
    Interner<String> pool = Interners.newStrongInterner();
    assertThrows(NullPointerException.class, () -> pool.intern(null));
  }

  public void testStrong_builder() {

    String not = new String("a");

    Interner<String> pool = Interners.newStrongInterner();
    assertThat(pool.intern(canonical)).isSameInstanceAs(canonical);
    assertThat(pool.intern(not)).isSameInstanceAs(canonical);
  }

  public void testStrong_null() {
    Interner<String> pool = Interners.newStrongInterner();
    assertThrows(NullPointerException.class, () -> pool.intern(null));
  }

  public void testStrong_builder() {

   *     be unique to the built instance of the ThreadFactory and will be assigned sequentially. For
   *     example, {@code "rpc-pool-%d"} will generate thread names like {@code "rpc-pool-0"}, {@code
   *     "rpc-pool-1"}, {@code "rpc-pool-2"}, etc.
   * @return this for the builder pattern
   */
  @CanIgnoreReturnValue
  public ThreadFactoryBuilder setNameFormat(String nameFormat) {

  wget "http://old-releases.ubuntu.com/ubuntu/pool/main/e/eglibc/libc6_2.12.1-0ubuntu6_amd64.deb" && \
      unar "libc6_2.12.1-0ubuntu6_amd64.deb" && \
      tar -C "${TARGET}" -xvzf "libc6_2.12.1-0ubuntu6_amd64/data.tar.gz" && \
      rm -rf "libc6_2.12.1-0ubuntu6_amd64.deb" "libc6_2.12.1-0ubuntu6_amd64"
  # Download binary glibc 2.12 development library release.

 1. It uses the URL and configured OkHttpClient to create an **address**. This address specifies how we'll connect to the webserver.
 2. It attempts to retrieve a connection with that address from the **connection pool**.
 3. If it doesn't find a connection in the pool, it selects a **route** to attempt. This usually means making a DNS request to get the server's IP addresses. It then selects a TLS version and proxy server if necessary.

    val id: Int,
  ) : RoutePlanner.Plan {
    var planningThrowable: Throwable? = null
    var canceled = false
    var connectState = ConnectState.READY
    val connection =
      factory.newConnection(
        pool = pool,
        route = factory.newRoute(address),
        idleAtNanos = defaultConnectionIdleAtNanos,
      )
    var retry: FakePlan? = null
    var retryTaken = false
    var yieldBeforePlanReturns = false

    // pool ID but a thread ID of 2.
    Thread thread2 = threadFactory.newThread(monitoredRunnable);
    checkThreadPoolName(thread2, 2);
    assertThat(thread2.getName().substring(0, thread.getName().lastIndexOf('-')))
        .isEqualTo(thread.getName().substring(0, thread.getName().lastIndexOf('-')));

    // Building again should give us a different pool ID.
    ThreadFactory threadFactory2 = builder.build();

 *   <li><b>Total nodes:</b> 65535 (16-bit index in the trie)
 *   <li><b>String pool size:</b> 65535 characters (16-bit offset in the String Pool)
 *   <li><b>Max children per node:</b> 2047 (11-bit count in the bitfield)
 * </ul>
 *
 * <p>As of Jan 2026, the capacity usage is approximately:
 *
 * <ul>
 *   <li>Total nodes: ~16% (10k / 65k)
 *   <li>String pool size: ~79% (52k / 65k)
 *   <li>Max children per node: ~71% (1.5k / 2k)
 * </ul>

        .build()
    val request = Request(server.url("/"))
    val response1 = client.newCall(request).execute()
    assertThat(response1.body.string()).isEqualTo("a")

    // Give the thread pool a chance to evict.
    Thread.sleep(500)
    val response2 = client.newCall(request).execute()
    assertThat(response2.body.string()).isEqualTo("b")
    assertThat(server.takeRequest().exchangeIndex).isEqualTo(0)

    // pool ID but a thread ID of 2.
    Thread thread2 = threadFactory.newThread(monitoredRunnable);
    checkThreadPoolName(thread2, 2);
    assertThat(thread2.getName().substring(0, thread.getName().lastIndexOf('-')))
        .isEqualTo(thread.getName().substring(0, thread.getName().lastIndexOf('-')));

    // Building again should give us a different pool ID.
    ThreadFactory threadFactory2 = builder.build();