/**
   * Invoked when the HTTP connection has been closed normally.
   *
   * No further calls to this listener will be made.
   */
  open fun onClosed(eventSource: EventSource) {
  }

  /**
   * Invoked when an event source has been closed due to an error reading from or writing to the
   * network. Incoming events may have been lost. No further calls to this listener will be made.
   */
  open fun onFailure(
    eventSource: EventSource,

    val connection = this.connection!!
    connection.assertLockHeld()

    val calls = connection.calls
    val index = calls.indexOfFirst { it.get() == this@RealCall }
    check(index != -1)

    calls.removeAt(index)
    this.connection = null

    if (calls.isEmpty()) {
      connection.idleAtNs = System.nanoTime()
      if (connectionPool.connectionBecameIdle(connection)) {

      data: String,
    )

    fun onRetryChange(timeMs: Long)
  }

  /**
   * Process the next event. This will result in a single call to [Callback.onEvent] *unless* the
   * data section was empty. Any number of calls to [Callback.onRetryChange] may occur while
   * processing an event.
   *
   * @return false when EOF is reached
   */
  @Throws(IOException::class)
  fun processNextEvent(): Boolean {
    var id = lastId

   * called on the {@code TypeVariable} instance has the same name as one of the public methods of
   * {@link TypeVariableImpl}, the proxy calls the same method on its instance of {@code
   * TypeVariableImpl}. Otherwise it throws {@link UnsupportedOperationException}; this should only

 *
 * <p>This uses the same efficient implementation as {@link Ordering#leastOf(Iterable, int)},
 * offering expected O(n + k log k) performance (worst case O(n log k)) for n calls to {@link
 * #offer} and a call to {@link #topK}, with O(k) memory. In comparison, quickselect has the same
 * asymptotics but requires O(n) memory, and a {@code PriorityQueue} implementation takes O(n log

   * called on the {@code TypeVariable} instance has the same name as one of the public methods of
   * {@link TypeVariableImpl}, the proxy calls the same method on its instance of {@code
   * TypeVariableImpl}. Otherwise it throws {@link UnsupportedOperationException}; this should only

=== ":material-language-kotlin: Kotlin"
    ```kotlin
      private val executor = Executors.newScheduledThreadPool(1)
      private val client = OkHttpClient()

      fun run() {