/**
 * A bimap (or "bidirectional map") is a map that preserves the uniqueness of its values as well as
 * that of its keys. This constraint enables bimaps to support an "inverse view", which is another
 * bimap containing the same entries as this bimap but with reversed keys and values.
 *
 * <h3>Implementations</h3>
 *
 * <ul>
 *   <li>{@link ImmutableBiMap}
 *   <li>{@link HashBiMap}
 *   <li>{@link EnumBiMap}

    * So, by using FastAPI you are saving development time, bugs, lines of code, and you would probably get the same performance (or better) you would if you didn't use it (as you would have to implement it all in your code).

http://127.0.0.1:8000/items/
```

would be the same as going to:

```
http://127.0.0.1:8000/items/?skip=0&limit=10
```

But if you go to, for example:

```
http://127.0.0.1:8000/items/?skip=20
```

The parameter values in your function will be:

* `skip=20`: because you set it in the URL
* `limit=10`: because that was the default value

## Optional parameters

///

/// note | "Technical Details"

You could also use `from starlette.responses import JSONResponse`.

**FastAPI** provides the same `starlette.responses` as `fastapi.responses` just as a convenience for you, the developer. But most of the available responses come directly from Starlette. The same with `status`.

///

## OpenAPI and API docs

object file can then be combined with other objects into a package archive.

# Command Line

Usage:

	go tool asm [flags] file

The specified file must be a Go assembly file.
The same assembler is used for all target operating systems and architectures.
The GOOS and GOARCH environment variables set the desired target.

Flags:

	-D name[=value]
		Predefine symbol name with an optional simple value.

In Pydantic version 1 the method to parse and validate an object was `Item.parse_obj()`, in Pydantic version 2, the method is called `Item.model_validate()`.

///

/// tip

Here we reuse the same Pydantic model.

But the same way, we could have validated it in some other way.

{* ../../docs_src/openapi_webhooks/tutorial001.py hl[9:13,36:53] *}

The webhooks that you define will end up in the **OpenAPI** schema and the automatic **docs UI**.

/// info

The `app.webhooks` object is actually just an `APIRouter`, the same type you would use when structuring your app with multiple files.

You could also use `from starlette.requests import Request` and `from starlette.responses import JSONResponse`.

**FastAPI** provides the same `starlette.responses` as `fastapi.responses` just as a convenience for you, the developer. But most of the available responses come directly from Starlette. The same with `Request`.

///

## Override the default exception handlers

**FastAPI** has some default exception handlers.

# Header Parameters

You can define Header parameters the same way you define `Query`, `Path` and `Cookie` parameters.

## Import `Header`

First import `Header`:

//// tab | Python 3.10+

```Python hl_lines="3"
{!> ../../docs_src/header_params/tutorial001_an_py310.py!}
```

////

//// tab | Python 3.9+

```Python hl_lines="3"
{!> ../../docs_src/header_params/tutorial001_an_py39.py!}
```

////

// per device in `underlying_devices`. Implicit copies off of the device throw
// an error.
//
// All component tensors must have the same dtype. Currently they must also have
// the same shape, although this requirement may be relaxed in the future.
//
// `device_name` must not name an existing physical or custom device (see