That is not the same as declaring default values like would be with:

```Python
    first_name="john", last_name="doe"
```

It's a different thing.

We are using colons (`:`), not equals (`=`).

And adding type hints normally doesn't change what happens from what would happen without them.

But now, imagine you are again in the middle of creating that function, but with type hints.

        final SearchEngineClient searchEngineClient = ComponentUtil.getSearchEngineClient();

        if (logger.isDebugEnabled()) {
            logger.debug("Adding document: url={}", dataMap.get(fessConfig.getIndexFieldUrl()));
        }

        //   required check
        final Object urlObj = dataMap.get(fessConfig.getIndexFieldUrl());
        if (urlObj == null) {

   *     value
   */
  public static UnsignedInteger valueOf(String string, int radix) {
    return fromIntBits(UnsignedInts.parseUnsignedInt(string, radix));
  }

  /**
   * Returns the result of adding this and {@code val}. If the result would have more than 32 bits,
   * returns the low 32 bits of the result.
   *
   * @since 14.0
   */
  public UnsignedInteger plus(UnsignedInteger val) {

@SuppressWarnings("rawtypes") // https://github.com/google/guava/issues/989
@DoNotMock("Use ImmutableRangeSet or TreeRangeSet")
@GwtIncompatible
public interface RangeSet<C extends Comparable> {
  // TODO(lowasser): consider adding default implementations of some of these methods

  // Query methods

  /** Determines whether any of this range set's member ranges contains {@code value}. */
  boolean contains(C value);

  /**

So, we get a Pydantic model from the data in another Pydantic model.

#### Unpacking a `dict` and extra keywords { #unpacking-a-dict-and-extra-keywords }

And then adding the extra keyword argument `hashed_password=hashed_password`, like in:

```Python
UserInDB(**user_in.model_dump(), hashed_password=hashed_password)
```

...ends up being like:

```Python
UserInDB(

<div class="termy">

```console
$ pip install "uvicorn[standard]"

---> 100%
```

</div>

A similar process would apply to any other ASGI server program.

/// tip

By adding the `standard`, Uvicorn will install and use some recommended extra dependencies.

That including `uvloop`, the high-performance drop-in replacement for `asyncio`, that provides the big concurrency performance boost.

## The normal **FastAPI** app { #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

	if err != nil {
		return nil, err
	}

	// Verify if the authToken already contains
	// <Key> <Token> like format, if this is
	// already present we can blindly use the
	// authToken as is instead of adding 'Bearer'
	tokens := strings.Fields(target.args.AuthToken)
	switch len(tokens) {
	case 2:
		req.Header.Set("Authorization", target.args.AuthToken)
	case 1:

The `str | None` (Python 3.10+) or `Union` in `Union[str, None]` (Python 3.9+) 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 { #without-pydantic }