*/
  @CanIgnoreReturnValue
  public static UnsignedLong valueOf(String string, int radix) {
    return fromLongBits(UnsignedLongs.parseUnsignedLong(string, radix));
  }

  /**
   * Returns the result of adding this and {@code val}. If the result would have more than 64 bits,
   * returns the low 64 bits of the result.
   *
   * @since 14.0
   */
  public UnsignedLong plus(UnsignedLong val) {

import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * CompactLinkedHashSet is an implementation of a Set, which a predictable iteration order that
 * matches the insertion order. All optional operations (adding and removing) are supported. All
 * elements, including {@code null}, are permitted.
 *
 * <p>{@code contains(x)}, {@code add(x)} and {@code remove(x)}, are all (expected and amortized)

   */
  @CanIgnoreReturnValue
  public static UnsignedLong valueOf(String string, int radix) {
    return fromLongBits(UnsignedLongs.parseUnsignedLong(string, radix));
  }

  /**
   * Returns the result of adding this and {@code val}. If the result would have more than 64 bits,
   * returns the low 64 bits of the result.
   *
   * @since 14.0
   */
  public UnsignedLong plus(UnsignedLong val) {

The `str | None` (Python 3.10+) or `Union` in `Union[str, None]` (Python 3.8+) is not used by FastAPI to determine that the value is not required, it will know it's not required because it has a default value of `= None`.

But adding the type annotations will allow your editor to give you better support and detect errors.

///

## Without Pydantic

## The normal **FastAPI** app

Let's first see how the normal API app would look like before adding the callback.

It will have a *path operation* that will receive an `Invoice` body, and a query parameter `callback_url` that will contain the URL for the callback.

			//   expectation  =  "100-continue" | expectation-extension
			//
			// So it safe to assume that '100-continue' is what would
			// be sent, for the time being keep this work around.
			// Adding a *TODO* to remove this later when Golang server
			// doesn't filter out the 'Expect' header.
			extractedSignedHeaders.Set(header, "100-continue")
		case "host":
			// Go http server removes "host" from Request.Header

different strategy. ### Configuration Refer the [Values file](./values.yaml) for all the possible config fields. You can specify each parameter using the `--set key=value[,key=value]` argument to `helm install`. For example, ```bash helm install --name my-release --set persistence.size=1Ti minio/minio ``` The above command deploys MinIO server with a 1Ti backing persistent volume. Alternately, you can provide a YAML file that specifies parameter values while installing the chart. For example, ```bash...

* **Document** the API using OpenAPI:
    * which is then used by the automatic interactive documentation user interfaces.

This might all sound abstract. Don't worry. You'll see all this in action in the [Tutorial - User Guide](tutorial/index.md){.internal-link target=_blank}.

  // safely publish these objects and we won't need this whole discussion.
  // TODO(user,lukes): consider adding volatile to all these fields since in current known JVMs
  // that should resolve the issue. This comes at the cost of adding more write barriers to the
  // implementations.

  private Futures() {}

  /**

different strategy. ### Configuration Refer the [Values file](./values.yaml) for all the possible config fields. You can specify each parameter using the `--set key=value[,key=value]` argument to `helm install`. For example, ```bash helm install --name my-release --set persistence.size=1Ti minio/minio ``` The above command deploys MinIO server with a 1Ti backing persistent volume. Alternately, you can provide a YAML file that specifies parameter values while installing the chart. For example, ```bash...