{!> ../../../docs_src/extra_models/tutorial003.py!}
    ```

### `Union` in Python 3.10

In this example we pass `Union[PlaneItem, CarItem]` as the value of the argument `response_model`.

Because we are passing it as a **value to an argument** instead of putting it in a **type annotation**, we have to use `Union` even in Python 3.10.

If it was in a type annotation we could have used the vertical bar, as:

```Python

// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package cmd

import (
	"errors"
)

// errInvalidArgument means that input argument is invalid.
var errInvalidArgument = errors.New("Invalid arguments specified")

// errMethodNotAllowed means that method is not allowed.
var errMethodNotAllowed = errors.New("Method not allowed")

// errSignatureMismatch means signature did not match.

        println("internal fun $CONVERT_ARGUMENT(argument: Any?, analysisSession: KtFirAnalysisSession): Any? {")
        withIndent {
            println("return $CONVERT_ARGUMENT(argument, analysisSession.firSymbolBuilder)")
        }
        println("}")
        println()

        println("private fun $CONVERT_ARGUMENT(argument: Any?, firSymbolBuilder: KtSymbolByFirBuilder): Any? {")
        withIndent {

If you are not familiar with the `UserInDB(**result.value)`, <a href="https://docs.python.org/3/glossary.html#term-argument" class="external-link" target="_blank">it is using `dict` "unpacking"</a>.

It will take the `dict` at `result.value`, and take each of its keys and values and pass them as key-values to `UserInDB` as keyword arguments.

So, if the `dict` contains:

```Python
{
    "username": "johndoe",

    Subscriber subscriber = Subscriber.create(bus, this, method);

    subscriber.invokeSubscriberMethod(FIXTURE_ARGUMENT);

    assertTrue("Subscriber must call provided method", methodCalled);
    assertTrue(
        "Subscriber argument must be exactly the provided object.",
        methodArgument == FIXTURE_ARGUMENT);
  }

  public void testInvokeSubscriberMethod_exceptionWrapping() throws Throwable {

        is FirTypeParameterSymbol -> convertArgument(argument, firSymbolBuilder)
        is FirCallableSymbol<*> -> convertArgument(argument, firSymbolBuilder)
        is FirClassSymbol<*> -> convertArgument(argument, firSymbolBuilder)
        is FirClassLikeSymbol<*> -> convertArgument(argument, firSymbolBuilder)
        is FirBasedSymbol<*> -> convertArgument(argument, firSymbolBuilder)

    Subscriber subscriber = Subscriber.create(bus, this, method);

    subscriber.invokeSubscriberMethod(FIXTURE_ARGUMENT);

    assertTrue("Subscriber must call provided method", methodCalled);
    assertTrue(
        "Subscriber argument must be exactly the provided object.",
        methodArgument == FIXTURE_ARGUMENT);
  }

  public void testInvokeSubscriberMethod_exceptionWrapping() throws Throwable {

    parser = argparse.ArgumentParser(
        description="Compare kubernetes yaml files")

    parser.add_argument("orig")
    parser.add_argument("new")
    parser.add_argument("--ignore-namespace", action="store_true", default=False,
                        help="Ignore namespace during comparison")
    parser.add_argument("--ignore-labels", action="store_true", default=False,

     * @return the collection result, never {@code null}
     * @throws DependencyCollectorException if the dependency tree could not be built
     * @throws IllegalArgumentException if an argument is null or invalid
     *
     * @see DependencyCollector#collect(Session, Project)
     * @see DependencyCollector#collect(Session, DependencyCoordinate)
     * @see DependencyCollector#collect(Session, Artifact)
     */

   *   <li>{@code proxy.equals(argument)} returns true if:
   *       <ul>
   *         <li>{@code proxy} and {@code argument} are of the same type
   *         <li>and {@link AbstractInvocationHandler#equals} returns true for the {@link
   *             InvocationHandler} of {@code argument}
   *       </ul>
   *   <li>other method calls are dispatched to {@link #handleInvocation}.