```

</div>

Then go to the `/docs` UI, you will see that **FastAPI** is using these **models** to **document** the API, and it will use them to **serialize** and **validate** the data too.

<div class="screenshot">
<img src="/img/tutorial/sql-databases/image01.png">
</div>

## Update the App with Multiple Models { #update-the-app-with-multiple-models }

	log.SetPrefix("go_android_exec: ")
	exitCode, err := runMain()
	if err != nil {
		log.Fatal(err)
	}
	os.Exit(exitCode)
}

func runMain() (int, error) {
	// Concurrent use of adb is flaky, so serialize adb commands.
	// See https://github.com/golang/go/issues/23795 or
	// https://issuetracker.google.com/issues/73230216.
	lockPath := filepath.Join(os.TempDir(), "go_android_exec-adb-lock")

        SsoLoginException originalException = new SsoLoginException(message, cause);

        // Serialize the exception
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        ObjectOutputStream oos = new ObjectOutputStream(baos);
        oos.writeObject(originalException);
        oos.close();

        // Deserialize the exception
        ByteArrayInputStream bais = new ByteArrayInputStream(baos.toByteArray());

        // When - Serialize
        java.io.ByteArrayOutputStream baos = new java.io.ByteArrayOutputStream();
        java.io.ObjectOutputStream oos = new java.io.ObjectOutputStream(baos);
        oos.writeObject(exception);
        oos.close();

        // And deserialize
        java.io.ByteArrayInputStream bais = new java.io.ByteArrayInputStream(baos.toByteArray());

    //                                                                         ===========

    /**
     * Serializes a map to a JSON string.
     *
     * @param map the map to serialize.
     * @return the JSON string, or {@code "{}"} on failure.
     */
    protected String toJson(final Map<String, Object> map) {
        try {

	"syscall"
)

const debug = false

var tmpdir string

var (
	devID    string
	appID    string
	teamID   string
	bundleID string
	deviceID string
)

// lock is a file lock to serialize iOS runs. It is global to avoid the
// garbage collector finalizing it, closing the file and releasing the
// lock prematurely.
var lock *os.File

func main() {
	log.SetFlags(0)
	log.SetPrefix("go_ios_exec: ")

import json
from typing import Annotated, Any

from annotated_doc import Doc
from fastapi.encoders import jsonable_encoder
from starlette.responses import HTMLResponse


def _html_safe_json(value: Any) -> str:
    """Serialize a value to JSON with HTML special characters escaped.

    This prevents injection when the JSON is embedded inside a <script> tag.
    """
    return (
        json.dumps(value)
        .replace("<", "\\u003c")

    }
    return false;
  }

  @Override
  public String toString() {
    return asMapOfRanges().toString();
  }

  /**
   * This class is used to serialize ImmutableRangeMap instances. Serializes the {@link
   * #asMapOfRanges()} form.
   */
  private static final class SerializedForm<K extends Comparable<?>, V> implements Serializable {

    }
    return false;
  }

  @Override
  public String toString() {
    return asMapOfRanges().toString();
  }

  /**
   * This class is used to serialize ImmutableRangeMap instances. Serializes the {@link
   * #asMapOfRanges()} form.
   */
  private static final class SerializedForm<K extends Comparable<?>, V> implements Serializable {

            )
        except ValidationError as exc:
            return None, _regenerate_error_with_loc(
                errors=exc.errors(include_url=False), loc_prefix=loc
            )

    def serialize(
        self,
        value: Any,
        *,
        mode: Literal["json", "python"] = "json",
        include: IncEx | None = None,
        exclude: IncEx | None = None,
        by_alias: bool = True,