CountingSupplier countingSupplier = new CountingSupplier();
    Supplier<Integer> memoizedSupplier = Suppliers.memoize(countingSupplier);
    assertThat(memoizedSupplier.toString()).isEqualTo("Suppliers.memoize(CountingSupplier)");
    checkMemoize(countingSupplier, memoizedSupplier);
    // Calls to the original memoized supplier shouldn't affect its copy.
    Object unused = memoizedSupplier.get();
    assertThat(memoizedSupplier.toString())

    CountingSupplier countingSupplier = new CountingSupplier();
    Supplier<Integer> memoizedSupplier = Suppliers.memoize(countingSupplier);
    assertThat(memoizedSupplier.toString()).isEqualTo("Suppliers.memoize(CountingSupplier)");
    checkMemoize(countingSupplier, memoizedSupplier);
    // Calls to the original memoized supplier shouldn't affect its copy.
    Object unused = memoizedSupplier.get();
    assertThat(memoizedSupplier.toString())

            if (configuration == null) {
                configuration = XmlNode.newInstance("configuration");
            }
            UnaryOperator<String> cb = Interpolator.memoize(callback);
            UnaryOperator<String> it = s -> interpolator.interpolate(s, cb);
            configuration = new ExtensionInterpolator(it).transform(configuration);

            binder.bind(XmlNode.class)

   * delegating calls until it returns valid data.
   *
   * <p>If {@code delegate} is an instance created by an earlier call to {@code memoize}, it is
   * returned directly.
   */
  public static <T extends @Nullable Object> Supplier<T> memoize(Supplier<T> delegate) {
    if (delegate instanceof NonSerializableMemoizingSupplier
        || delegate instanceof MemoizingSupplier) {
      return delegate;
    }

        return chain(List.of(functions));
    }

    /**
     * Memoizes a given function that takes a String input and produces a String output.
     * This method creates a new function that caches the results of the original function,
     * improving performance for repeated calls with the same input.
     *
     * @param callback The original function to be memoized. It takes a String as input and returns a String.

            if (configuration == null) {
                configuration = XmlNode.newInstance("configuration");
            }
            UnaryOperator<String> cb = Interpolator.memoize(callback);
            UnaryOperator<String> it = s -> interpolator.interpolate(s, cb);
            configuration = new ExtensionInterpolator(it).transform(configuration);

            binder.bind(XmlNode.class)

        break;
      case TERMINATED:
      case FAILED:
        throw new AssertionError();
    }
  }

  private void enqueueFailedEvent(State from, Throwable cause) {
    // can't memoize this one due to the exception
    listeners.enqueue(
        new ListenerCallQueue.Event<Listener>() {
          @Override
          public void call(Listener listener) {
            listener.failed(from, cause);

        break;
      case TERMINATED:
      case FAILED:
        throw new AssertionError();
    }
  }

  private void enqueueFailedEvent(State from, Throwable cause) {
    // can't memoize this one due to the exception
    listeners.enqueue(
        new ListenerCallQueue.Event<Listener>() {
          @Override
          public void call(Listener listener) {
            listener.failed(from, cause);

* «the `Response`»: «`Response`» (keep as code identifier)

* «deployment»: «déploiement»
* «to upgrade»: «mettre à niveau»

* «deprecated»: «déprécié»
* «to deprecate»: «déprécier»

* «cheat sheet»: «aide-mémoire»

Let's see the previous example again:

{* ../../docs_src/response_status_code/tutorial001_py39.py hl[6] *}

`201` is the status code for "Created".

But you don't have to memorize what each of these codes mean.

You can use the convenience variables from `fastapi.status`.

{* ../../docs_src/response_status_code/tutorial002_py39.py hl[1,6] *}