# Body - Nested Models { #body-nested-models }

With **FastAPI**, you can define, validate, document, and use arbitrarily deeply nested models (thanks to Pydantic).

## List fields { #list-fields }

You can define an attribute to be a subtype. For example, a Python `list`:

{* ../../docs_src/body_nested_models/tutorial001_py310.py hl[12] *}

This will make `tags` be a list, although it doesn't declare the type of the elements of the list.

				"Unable to validate credentials inherited from the secret file(s)")
		}
		if accessKey != "" {
			os.Setenv(config.EnvRootUser, accessKey)
		}
	}

	if env.IsSet(config.EnvSecretKeyFile) {
		secretKey, err := readFromSecret(env.Get(config.EnvSecretKeyFile, ""))
		if err != nil {
			logger.Fatal(config.ErrInvalidCredentials(err),
				"Unable to validate credentials inherited from the secret file(s)")

     * @return HTML response for the web authentication edit form
     */
    @Execute
    @Secured({ ROLE })
    public HtmlResponse edit(final EditForm form) {
        validate(form, messages -> {}, this::asListHtml);
        final String id = form.id;
        webAuthenticationService.getWebAuthentication(id).ifPresent(entity -> {
            copyBeanToBean(entity, form, op -> {});

            assertEquals(0, flag & (flag - 1), "Flag should be power of 2: " + Integer.toHexString(flag));
        }

        @Test
        @DisplayName("Should validate all constants are unique")
        void shouldHaveUniqueConstants() {
            int[] accessConstants = { ACE.FILE_READ_DATA, ACE.FILE_WRITE_DATA, ACE.FILE_APPEND_DATA, ACE.FILE_READ_EA, ACE.FILE_WRITE_EA,

 - ACTION REQUIRED:
  
  vendor: Updated `k8s.io/system-validators` to `v1.12.1`. The cgroups validator now throws an error instead of a warning if cgroups v1 is detected on the host and the provided KubeletVersion is `v1.35` or newer.
  

     *
     * @param form the login form containing username and password
     * @return the HTML response after login attempt
     */
    @Execute
    public HtmlResponse login(final LoginForm form) {
        validate(form, messages -> {}, () -> asIndexPage(form));
        verifyToken(() -> asIndexPage(form));
        final String username = form.username;
        final String password = form.password;
        form.clearSecurityInfo();

            for (MavenPluginDependenciesValidator dependenciesValidator : dependenciesValidators) {
                dependenciesValidator.validate(session, pluginArtifact, result);
            }

            pluginArtifact = result.getArtifact();

            if (logger.isWarnEnabled() && !result.getRelocations().isEmpty()) {
                String message =

        <artifactId>maven-it-plugin-dependency-resolution</artifactId>
        <version>2.1-SNAPSHOT</version>
        <executions>
          <execution>
            <id>compile-classpath</id>
            <phase>validate</phase>
            <goals>
              <goal>compile</goal>
            </goals>
            <configuration>
              <compileClassPath>${project.build.directory}/compile.classpath</compileClassPath>

import com.vanniktech.maven.publish.JavadocJar
import com.vanniktech.maven.publish.KotlinJvm

plugins {
  kotlin("jvm")
  id("org.jetbrains.dokka")
  id("com.vanniktech.maven.publish.base")
  id("binary-compatibility-validator")
}

project.applyOsgi(
  "Export-Package: okhttp3.sse",
  "Bundle-SymbolicName: com.squareup.okhttp3.sse"
)

project.applyJavaModules("okhttp3.sse")

dependencies {
  api(projects.okhttp)

		}
		return false, azureToObjectError(err, az.Bucket, az.Prefix)
	}

	return len(resp.Segment.BlobItems) > 0, nil
}

type azureConf struct {
	madmin.TierAzure
}

func (conf azureConf) Validate() error {
	switch {
	case conf.AccountName == "":
		return errors.New("the account name is required")