You can use Pydantic's model configuration to `forbid` any `extra` fields:

{* ../../docs_src/header_param_models/tutorial002_an_py310.py hl[10] *}

If a client tries to send some **extra headers**, they will receive an **error** response.

For example, if the client tries to send a `tool` header with a value of `plumbus`, they will receive an **error** response telling them that the header parameter `tool` is not allowed:

```json
{

## Obtener el `username` y `password`

Vamos a usar las utilidades de seguridad de **FastAPI** para obtener el `username` y `password`.

OAuth2 especifica que cuando se utiliza el "password flow" (que estamos usando), el cliente/usuario debe enviar campos `username` y `password` como form data.

Y la especificación dice que los campos deben llamarse así. Por lo que `user-name` o `email` no funcionarían.

 *  Fix a bug in `Content-Length` reporting for gzipped streams in the Apache
    HTTP client adapter. (thanks kwuollett)
 *  Work around the Alcatel `getByInetAddress` bug (thanks k.kocel)
 *  Be more aggressive about testing pooled sockets before reuse. (thanks
    warpspin)
 *  Include `Content-Type` and `Content-Encoding` in the Apache HTTP client
    adapter. (thanks kwuollett)
 *  Add a media type class to OkHttp.

     * @param config the client configuration
     * @param controlCode the IOCTL control code
     */
    public Smb2IoctlRequest(final Configuration config, final int controlCode) {
        this(config, controlCode, Smb2Constants.UNSPECIFIED_FILEID);
    }

    /**
     * Constructs an SMB2 IOCTL request with a specified file ID
     * @param config the client configuration

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common;

import com.google.gwt.core.client.EntryPoint;

/**
 * A dummy entry point to convince Maven to compile our classes.
 *
 * @author Chris Povirk
 */
public class ForceGuavaCompilationEntryPoint implements EntryPoint {
  @Override

    protected static final String SPNEGO_LOGIN_SERVER_MODULE = "spnego.login.server.module";

    /** Configuration key for login client module name. */
    protected static final String SPNEGO_LOGIN_CLIENT_MODULE = "spnego.login.client.module";

    /** Configuration key for Kerberos configuration file path. */
    protected static final String SPNEGO_KRB5_CONF = "spnego.krb5.conf";

/* jcifs smb client library in Java
 * Copyright (C) 2000  "Michael B. Allen" <jcifs at samba dot org>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,

/* jcifs smb client library in Java
 * Copyright (C) 2005  "Michael B. Allen" <jcifs at samba dot org>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common;

import com.google.gwt.core.client.EntryPoint;

/**
 * A dummy entry point for our tests.
 *
 * @author Chris Povirk
 */
public class GuavaTestsEntryPoint implements EntryPoint {
  @Override
  public void onModuleLoad() {}

with OkHttp 3.x: must use `object :` with OkHttp 4.x:

Kotlin calling OkHttp 3.x:

```kotlin
val client = OkHttpClient.Builder()
    .dns { hostname -> InetAddress.getAllByName(hostname).toList() }
    .build()
```

Kotlin calling OkHttp 4.x:

```kotlin
val client = OkHttpClient.Builder()
    .dns(object : Dns {
      override fun lookup(hostname: String) =