**FastAPI** is all based on these type hints, they give it many advantages and benefits.

But even if you never use **FastAPI**, you would benefit from learning a bit about them.

/// note

If you are a Python expert, and you already know everything about type hints, skip to the next chapter.

///

## Motivation

Let's start with a simple example:

     *
     * @param material
     *            The raw Type-3 material used to construct this message.
     * @throws IOException
     *             If an error occurs while parsing the material.
     */
    public Type3Message ( byte[] material ) throws IOException {
        parse(material);
    }


    /**
     * Returns the default flags for a generic Type-3 message in the

  // Specifies the number of retries before marking this job failed.
  // Defaults to 6
  // +optional
  optional int32 backoffLimit = 7;

  // A label query over pods that should match the pod count.
  // Normally, the system sets this field for you.
  // More info: https://kubernetes.io/docs/concepts/overview/working-with-objects/labels/#label-selectors
  // +optional

//   - http://docs.aws.amazon.com/AmazonS3/latest/API/sigv4-streaming.html
//
// returns signature, error otherwise if the signature mismatches or any other
// error while parsing and validating.
func calculateSeedSignature(r *http.Request, trailers bool) (cred auth.Credentials, signature string, region string, date time.Time, errCode APIErrorCode) {
	// Copy request.
	req := *r

 * <ul>
 *   <li>{@code [a..a]} : a singleton range
 *   <li>{@code [a..a); (a..a]} : {@linkplain #isEmpty empty} ranges; also valid
 *   <li>{@code (a..a)} : <b>invalid</b>; an exception will be thrown
 * </ul>
 *
 * <h3>Warnings</h3>
 *
 * <ul>
 *   <li>Use immutable value types only, if at all possible. If you must use a mutable type, <b>do
 *       not</b> allow the endpoint instances to mutate after the range is created!

   *
   * @since 7.0
   */
  public static <T extends @Nullable Object> List<T> reverse(List<T> list) {
    if (list instanceof ImmutableList) {
      // Avoid nullness warnings.
      List<?> reversed = ((ImmutableList<?>) list).reverse();
      @SuppressWarnings("unchecked")
      List<T> result = (List<T>) reversed;
      return result;
    } else if (list instanceof ReverseList) {

```console
$ uvicorn main:app --reload

INFO:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
INFO:     Started reloader process [28720]
INFO:     Started server process [28722]
INFO:     Waiting for application startup.
INFO:     Application startup complete.
```

</div>

<details markdown="1">
<summary><code>uvicorn main:app --reload</code> 명령에 관하여...</summary>

118BF         ; mapped                 ; 118DF         # 7.0  WARANG CITI CAPITAL LETTER VIYO
118C0..118E9  ; valid                                  # 7.0  WARANG CITI SMALL LETTER NGAA..WARANG CITI DIGIT NINE
118EA..118F2  ; valid                  ;      ; NV8    # 7.0  WARANG CITI NUMBER TEN..WARANG CITI NUMBER NINETY
118F3..118FE  ; disallowed                             # NA   <reserved-118F3>..<reserved-118FE>

MinIO is a High Performance Object Storage released under GNU Affero General Public License v3.0. It is API compatible with Amazon S3 cloud storage service. Use MinIO to build high performance infrastructure for machine learning, analytics and application data workloads.

  // field.  This field has a default value of 8.
  // +optional
  optional int32 handSize = 2;

  // `queueLengthLimit` is the maximum number of requests allowed to
  // be waiting in a given queue of this priority level at a time;
  // excess requests are rejected.  This value must be positive.  If
  // not specified, it will be defaulted to 50.
  // +optional
  optional int32 queueLengthLimit = 3;