/**
   * 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(

   * @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
   *     corresponding mappings exist in the current {@code TypeResolver} instance.
   */
  public TypeResolver where(Type formal, Type actual) {
    Map<TypeVariableKey, Type> mappings = new HashMap<>();

        result = runInterruptibly();
      }
    } catch (Throwable t) {
      restoreInterruptIfIsInterruptedException(t);
      error = t;
    } finally {
      // Attempt to set the task as done so that further attempts to interrupt will fail.
      if (!compareAndSet(currentThread, DONE)) {
        waitForInterrupt(currentThread);
      }
      if (run) {
        if (error == null) {

   * @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
   *     corresponding mappings exist in the current {@code TypeResolver} instance.
   */
  public TypeResolver where(Type formal, Type actual) {
    Map<TypeVariableKey, Type> mappings = new HashMap<>();

   * fewer than {@code k} have been offered, in the order specified by the factory used to create
   * this {@code TopKSelector}.
   *
   * <p>The returned list is an unmodifiable copy and will not be affected by further changes to
   * this {@code TopKSelector}. This method returns in O(k log k) time.
   */
  public List<T> topK() {
    @SuppressWarnings("nullness") // safe because we pass sort() a range that contains real Ts

        this.value = value;
      }

      T get() {
        /*
         * requireNonNull is safe because we call get() only if we've previously called set().
         *
         * (For further discussion of nullness, see the comment above the method.)
         */
        return requireNonNull(value);
      }
    }
    OptionalState state = new OptionalState();

   * two). These considerations lead us to have a field of type DuplicateKey in the Builder, which
   * will remember the first duplicate key we encountered. All later calls to buildOrThrow() can
   * mention that key with its values. Further duplicates might be added in the meantime but since
   * builders only ever accumulate entries it will always be valid to throw from buildOrThrow() with
   * the first duplicate.
   */

   *
   * @throws NullPointerException if {@code elements} contains a null element
   */
  public static <E> ImmutableList<E> copyOf(Iterator<? extends E> elements) {
    // We special-case for 0 or 1 elements, but going further is madness.
    if (!elements.hasNext()) {
      return of();
    }
    E first = elements.next();
    if (!elements.hasNext()) {
      return of(first);
    } else {

   * lookup would fail with an IllegalAccessException. That may then trigger use of Unsafe (possibly
   * with a warning under recent JVMs), or it may fall back even further to
   * AtomicReferenceFieldUpdaterAtomicHelper, which would fail with a similar problem to
   * VarHandleAtomicHelperMaker, forcing us all the way to SynchronizedHelper.
   *

   * lookup would fail with an IllegalAccessException. That may then trigger use of Unsafe (possibly
   * with a warning under recent JVMs), or it may fall back even further to
   * AtomicReferenceFieldUpdaterAtomicHelper, which would fail with a similar problem to
   * VarHandleAtomicHelperMaker, forcing us all the way to SynchronizedHelper.
   *