```Python hl_lines="18  22"
{!../../../docs_src/additional_responses/tutorial001.py!}
```

!!! note
    Keep in mind that you have to return the `JSONResponse` directly.

!!! info
    The `model` key is not part of OpenAPI.

    **FastAPI** will take the Pydantic model from there, generate the `JSON Schema`, and put it in the correct place.

// and against which we measure optimized parsers.
//
// parseIPSlow understands the following forms of IP addresses:
//   - Regular IPv4: 1.2.3.4
//   - IPv4 with many leading zeros: 0000001.0000002.0000003.0000004
//   - Regular IPv6: 1111:2222:3333:4444:5555:6666:7777:8888
//   - IPv6 with many leading zeros: 00000001:0000002:0000003:0000004:0000005:0000006:0000007:0000008
//   - IPv6 with zero blocks elided: 1111:2222::7777:8888

        then:
        timer.getElapsed() == "32 mins 40.322 secs"
    }

    def testHoursMinutesAndSeconds() {
        when:
        setTime(3, 2, 5, 111)

        then:
        timer.getElapsed() == "3 hrs 2 mins 5.111 secs"
    }

    def testHoursZeroMinutes() {
        when:
        setTime(1, 0, 32, 0)

        then:
        timer.getElapsed() == "1 hrs 0 mins 32.0 secs"
    }

go build -x -n main.go
stderr '"-I[^"]+c flags"' # find quoted c flags
! stderr '"-I[^"]+c flags".*"-I[^"]+c flags"' # don't find too many quoted c flags per line
stderr '"-L[^"]+ld flags"' # find quoted ld flags
! stderr '"-L[^"]+c flags".*"-L[^"]+c flags"' # don't find too many quoted ld flags per line

-- main.go --
package main
// #cgo CFLAGS: -I"c flags"
// #cgo LDFLAGS: -L"ld flags"
import "C"

        "Publish a java library" | "publish-a-java-library"
        "dash-dash"              | "dash-dash"
        " space prefix"          | "space-prefix"
        "invalid char ąść"       | "invalid-char"
        "many  separators -- "   | "many-separators"
        "--"                     | ""
    }

her eyes filled with tears again as she went on, `I must be Mabel
after all, and I shall have to go and live in that poky little
house, and have next to no toys to play with, and oh! ever so
many lessons to learn!  No, I've made up my mind about it; if I'm
Mabel, I'll stay down here!  It'll be no use their putting their
heads down and saying "Come up again, dear!"  I shall only look
up and say "Who am I then?  Tell me that first, and then, if I

	return x // ERROR "not enough (arguments to return|return values)\n\thave \(int\)\n\twant \(int, error\)"
}

func _() int {
	return 1, 2 // ERROR "too many (arguments to return|return values)\n\thave \(number, number\)\n\twant \(int\)"
}

func _() {
	return 1 // ERROR "too many (arguments to return|return values)\n\thave \(number\)\n\twant \(\)"

<img src="/img/tutorial/custom-response/image01.png">

## Available responses

Here are some of the available responses.

Keep in mind that you can use `Response` to return anything else, or even create a custom sub-class.

!!! note "Technical Details"
    You could also use `from starlette.responses import HTMLResponse`.

I will show you some of the main concepts you should probably keep in mind when deploying a **FastAPI** application (although most of it applies to any other type of web application).

// run

//go:build !js && !wasip1

// Copyright 2022 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// Issue 52127: Too many syntax errors in many files can
// cause deadlocks instead of displaying error messages
// correctly.

package main

import (
	"bytes"
	"fmt"
	"os"
	"os/exec"
	"path/filepath"
)

func main() {