}
        } else {
          // In the case of a concurrent remove, we might observe a zero value, which means another
          // thread is about to remove (element, existingCounter) from the map. Rather than wait,
          // we can just do that work here.
          AtomicInteger newCounter = new AtomicInteger(occurrences);

    // FRQ tries to load the Finalizer class (for the reference-collecting thread) in a few ways.
    // If the class is accessible to the system ClassLoader (ClassLoader.getSystemClassLoader())
    // then FRQ does not bother to load Finalizer.class through a separate ClassLoader. That happens
    // in our test environment, which foils the purpose of this test, so we disable the logic for

### Other utility functions { #other-utility-functions }

          }
        } else {
          // In the case of a concurrent remove, we might observe a zero value, which means another
          // thread is about to remove (element, existingCounter) from the map. Rather than wait,
          // we can just do that work here.
          AtomicInteger newCounter = new AtomicInteger(occurrences);

 *  Upgrade: [publicsuffix.org data][public_suffix]. This powers `HttpUrl.topPrivateDomain()`.
    It's also how OkHttp knows which domains can share cookies with one another.
 *  Upgrade: [Okio 3.2.0][okio_3_2_0].


## Version 4.10.0

_2022-06-12_

 *  Upgrade: [Kotlin 1.6.20][kotlin_1_6_20].
 *  Upgrade: [Okio 3.0.0][okio_3_0_0].

   *
   * @param formal The type whose type variables or itself is mapped to other type(s). It's almost
   *     always a bug if {@code formal} isn't a type variable and contains no type variable. Make
   *     sure you are passing the two parameters in the right order.
   * @param actual The type that the formal type variable(s) are mapped to. It can be or contain yet
   *     other type variables, in which case these type variables will be further resolved if

               * with two implementations, one that contains causeless Cancellation instances and
               * the other of which creates new Cancellation instances each time it's called? Yet
               * another alternative is to fill in a non-null value for each of the fields no matter
               * what and to just not use it if !GENERATE_CANCELLATION_CAUSES.
               */

// Checksum types must match.
func (c *Checksum) AddPart(other Checksum, size int64) error {
	if !other.Type.CanMerge() {
		return fmt.Errorf("checksum type cannot be merged")
	}
	if size == 0 {
		return nil
	}
	if !c.Type.Is(other.Type.Base()) {
		return fmt.Errorf("checksum type does not match got %s and %s", c.Type.String(), other.Type.String())
	}
	// If never set, just add first checksum.

{* ../../docs_src/websockets_/tutorial003_py310.py hl[79:81] *}

To try it out:

* Open the app with several browser tabs.
* Write messages from them.
* Then close one of the tabs.

That will raise the `WebSocketDisconnect` exception, and all the other clients will receive a message like:

```
Client #1596980209979 left the chat
```

/// tip

    nextTask.start()
    return nextTask
  }

  private interface SerialTask {
    /** Returns true if this task is ready to start. */
    fun isReady() = true

    /** Do this task's work, and then start another, such as by calling [startNextTask]. */
    fun start()
  }

  private object TestThreadSerialTask : SerialTask {
    override fun start() = error("unexpected call")
  }

  inner class RunnableSerialTask(