end
    end

    style V2 fill:#f9fff3
    style V1 fill:#fff6f0
    style V1Field fill:#fff6f0
    style V2Field fill:#f9fff3
```

In some cases, it's even possible to have both Pydantic v1 and v2 models in the same **path operation** in your FastAPI app:

{* ../../docs_src/pydantic_v1_in_v2/tutorial003_an_py310.py hl[2:3,6,12,21:22] *}

	writeSuccessResponseXML(w, encodeResponseList(response))
}

// ListObjectsV2MHandler - GET Bucket (List Objects) Version 2 with metadata.
// --------------------------
// This implementation of the GET operation returns some or all (up to 1000)
// of the objects in a bucket. You can use the request parameters as selection
// criteria to return a subset of the objects in a bucket.
//

            bytes,
            Doc(
                """
                The bytes to write to the file.
                """
            ),
        ],
    ) -> None:
        """
        Write some bytes to the file.

        You normally wouldn't use this from a file you read in a request.

        To be awaitable, compatible with async, this is run in threadpool.
        """
        return await super().write(data)

 *
 * <p>While it is recommended that service lifecycles be managed via this class, state transitions
 * initiated via other mechanisms do not impact the correctness of its methods. For example, if the
 * services are started by some mechanism besides {@link #startAsync}, the listeners will be invoked
 * when appropriate and {@link #awaitHealthy} will still work as expected.
 *

import org.eclipse.aether.repository.AuthenticationSelector;
import org.eclipse.aether.repository.MirrorSelector;
import org.eclipse.aether.repository.ProxySelector;

/**
 * Strictly internal component able to "extend" session in some way.
 *
 * @since 4.0.0
 */
interface RepositorySystemSessionExtender {
    void extend(
            MavenExecutionRequest mavenExecutionRequest,
            Map<String, Object> configProperties,

function urlForInput(t) {
    if (!t) {
        return null;
    }

    if (numericRE.test(t)) {
        if (t < 150000) {
            // We could use the golang.org/cl/ handler here, but
            // avoid some redirect latency and go right there, since
            // one is easy. (no server-side mapping)
            return "https://github.com/golang/go/issues/" + t;
        }
        return "https://golang.org/cl/" + t;
    }

import java.util.concurrent.atomic.AtomicIntegerFieldUpdater;
import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
import java.util.logging.Level;
import org.jspecify.annotations.Nullable;

/**
 * A helper which does some thread-safe operations for aggregate futures, which must be implemented
 * differently in GWT. Namely:
 *
 * <ul>
 *   <li>Lazily initializes a set of seen exceptions
 *   <li>Decrements a counter atomically
 * </ul>

@app.post("/invoices/", callbacks=invoices_callback_router.routes)
def create_invoice(invoice: Invoice, callback_url: HttpUrl | None = None):
    """
    Create an invoice.

    This will (let's imagine) let the API user (some external developer) create an
    invoice.

    And this path operation will:

    * Send the invoice to the client.
    * Collect the money from the client.

q: Annotated[str | None] = None
```

Both of those versions mean the same thing, `q` is a parameter that can be a `str` or `None`, and by default, it is `None`.

Now let's jump to the fun stuff. 🎉

## Add `Query` to `Annotated` in the `q` parameter { #add-query-to-annotated-in-the-q-parameter }

 * the License.
 */

package com.google.common.collect;

import com.google.common.annotations.GwtCompatible;

/**
 * Indicates whether an endpoint of some range is contained in the range itself ("closed") or not
 * ("open"). If a range is unbounded on a side, it is neither open nor closed on that side; the
 * bound simply does not exist.
 *
 * @since 10.0
 */
@GwtCompatible