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.

Prefer to use the `Annotated` version if possible.

///

```Python hl_lines="25"
{!> ../../docs_src/security/tutorial002.py!}
```

////

## Get the user

`get_current_user` will use a (fake) utility function we created, that takes a token as a `str` and returns our Pydantic `User` model:

//// tab | Python 3.10+

```Python hl_lines="19-22  26-27"
{!> ../../docs_src/security/tutorial002_an_py310.py!}
```

 *
 * <p>Note that although your APIs should be liberal in what they accept, your methods which
 * <i>return</i> iterables should make every attempt to return ones of the robust variety.
 *
 * <p>This testing utility is not thread-safe.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible
public final class MinimalIterable<E extends @Nullable Object> implements Iterable<E> {

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

limitations under the License.
==============================================================================*/
#include "tensorflow/c/eager/graph_function.h"

#include <utility>

#include "tensorflow/c/eager/abstract_function.h"
#include "tensorflow/core/framework/function.h"
#include "tensorflow/core/platform/status.h"

namespace tensorflow {
namespace tracing {
namespace graph {

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+