By default, what the method `.openapi()` does is check the property `.openapi_schema` to see if it has contents and return them.

If it doesn't, it generates them using the utility function at `fastapi.openapi.utils.get_openapi`.

And that function `get_openapi()` receives as parameters:

* `title`: The OpenAPI title, shown in the docs.
* `version`: The version of your API, e.g. `2.5.0`.

These examples are intentionally simple, but show how it all works.

In the chapters about security, there are utility functions that are implemented in this same way.

If you understood all this, you already know how those utility tools for security work underneath.

import org.eclipse.aether.metadata.AbstractMetadata;
import org.eclipse.aether.metadata.MergeableMetadata;
import org.eclipse.aether.metadata.Metadata;

/**
 * <strong>Warning:</strong> This is an internal utility class that is only public for technical reasons, it is not part
 * of the public API. In particular, this class can be changed or deleted without prior notice.
 *
 */
@Deprecated

import org.apache.maven.MavenExecutionException;
import org.apache.maven.execution.MavenExecutionRequest;
import org.apache.maven.project.MavenProject;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Utility class to extract {@link MavenProject} from the project graph during the execution phase based on optional or
 * required selectors.
 */
public final class ProjectSelector {

 * under the License.
 */
package org.apache.maven.repository.internal;

import org.eclipse.aether.DefaultRepositorySystemSession;
import org.eclipse.aether.util.graph.manager.ClassicDependencyManager;

/**
 * A utility class to assist in setting up a Maven-like repository system. Note: This component is meant to
 * assist those clients that employ the repository system outside of an IoC container, Maven plugins should instead

import org.apache.maven.settings.validation.SettingsValidator;

/**
 * A factory to create settings builder instances when no dependency injection is available. Note: This class
 * is only meant as a utility for developers that want to employ the settings builder outside of the Maven build system,
 * Maven plugins should always acquire settings builder instances via dependency injection. Developers might want to

And be compatible with all of them at the same time.

///

Create a utility function to hash a password coming from the user.

And another utility to verify if a received password matches the hash stored.

And another one to authenticate and return a user.

//// tab | Python 3.10+

import org.eclipse.aether.artifact.DefaultArtifact;
import org.eclipse.aether.repository.RemoteRepository;
import org.eclipse.aether.repository.RepositoryPolicy;

/**
 * <strong>Warning:</strong> This is an internal utility class that is only public for technical reasons, it is not part
 * of the public API. In particular, this class can be changed or deleted without prior notice.
 *
 * @deprecated since 4.0.0, use {@code maven-api-impl} jar instead

import java.util.Date;
import java.util.Locale;
import java.util.Properties;

import org.apache.maven.jline.MessageUtils;
import org.apache.maven.utils.Os;
import org.slf4j.Logger;

/**
 * Utility class used to report errors, statistics, application version info, etc.
 *
 */
public final class CLIReportingUtils {
    // CHECKSTYLE_OFF: MagicNumber
    public static final long MB = 1024 * 1024;

import java.util.Objects;

import org.apache.maven.building.Source;
import org.apache.maven.model.Model;

/**
 * Holds a model along with some auxiliary information. This internal utility class assists the model builder during POM
 * processing by providing a means to transport information that cannot be (easily) extracted from the model itself.
 *