Here are some additional ideas that might be useful when working with Python types.

## Using `Union` or `Optional` { #using-union-or-optional }

If your code for some reason can't use `|`, for example if it's not in a type annotation but in something like `response_model=`, instead of using the vertical bar (`|`) you can use `Union` from `typing`.

For example, you could declare that something could be a `str` or `None`:

```python

    /**
     * Gets the problems that were encountered during the settings building. Note that only problems of severity
     * {@link SettingsProblem.Severity#WARNING} and below are reported here. Problems with a higher severity level cause
     * the settings builder to fail with a {@link SettingsBuildingException}.
     *

	notificationEventsErrorsTotalMD     = NewCounterMD(notificationEventsErrorsTotal, "Events that were failed to be sent to the targets")
	notificationEventsSentTotalMD       = NewCounterMD(notificationEventsSentTotal, "Total number of events sent to the targets")
	notificationEventsSkippedTotalMD    = NewCounterMD(notificationEventsSkippedTotal, "Events that were skipped to be sent to the targets due to the in-memory queue being full")
)

You can import it directly from `fastapi`:

```python
from fastapi import Request
```

/// tip

When you want to define dependencies that should be compatible with both HTTP and WebSockets, you can define a parameter that takes an `HTTPConnection` instead of a `Request` or a `WebSocket`.

///

/**
 * Collects problems that are encountered during model building. The primary purpose of this component is to account for
 * the fact that the problem reporter has/should not have information about the calling context and hence cannot provide
 * an expressive source hint for the model problem. Instead, the source hint is configured by the model builder before

import static java.lang.annotation.ElementType.METHOD;
import static java.lang.annotation.ElementType.TYPE;
import static java.lang.annotation.RetentionPolicy.RUNTIME;

/**
 * Explicitly specifies the types that should be used for dependency injection.
 * <p>
 * This annotation allows you to limit which types of a bean should be available
 * for injection. It can be used to prevent unintended automatic binding of implemented

     *
     * @param problems The problems that cause this exception, may be {@code null}.
     */
    public SettingsBuildingException(List<SettingsProblem> problems) {
        super(toMessage(problems));

        this.problems = new ArrayList<>();
        if (problems != null) {
            this.problems.addAll(problems);
        }
    }

    /**
     * Gets the problems that caused this exception.
     *

     */
    public int getPointer() {
        return this.pointer;
    }

    /**
     * Validates the provided string against this structure's metadata.
     * Checks that the string length matches the expected length and that
     * null strings have a zero pointer.
     *
     * @param string the string to validate
     * @return the validated string
     * @throws PACDecodingException if validation fails
     */

client = TestClient(app)


def test_dependency_contextvars():
    """
    Check that custom middlewares don't affect the contextvar context for dependencies.

    The code before yield and the code after yield should be run in the same contextvar
    context, so that request_state_context_var.reset(contextvar_token).

    If they are run in a different context, that raises an error.
    """
    response = client.get("/user")

// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//