*    other properties.
 *
 * Certificates are signed by other certificates and a sequence of them is called a certificate
 * chain. The chain terminates in a self-signed "root" certificate. Signing certificates in the
 * middle of the chain are called "intermediates". Organizations that offer certificate signing are
 * called certificate authorities (CAs).
 *

@needs_pydanticv2
def test_pydanticv2():
    from pydantic import field_serializer

    class ModelWithDatetimeField(BaseModel):
        dt_field: datetime

        @field_serializer("dt_field")
        def serialize_datetime(self, dt_field: datetime):
            return dt_field.replace(microsecond=0, tzinfo=timezone.utc).isoformat()

    app = FastAPI()
    model = ModelWithDatetimeField(dt_field=datetime(2019, 1, 1, 8))

import time
from typing import Callable

from fastapi import APIRouter, FastAPI, Request, Response
from fastapi.routing import APIRoute


class TimedRoute(APIRoute):
    def get_route_handler(self) -> Callable:
        original_route_handler = super().get_route_handler()

        async def custom_route_handler(request: Request) -> Response:
            before = time.time()
            response: Response = await original_route_handler(request)

 */
package okhttp3.slack;

import java.util.List;
import okhttp3.HttpUrl;

/** See https://api.slack.com/methods/rtm.start. */
public final class RtmStartResponse {
  HttpUrl url;
  Object self;
  Object team;
  List<Object> users;
  List<Object> channels;
  List<Object> groups;
  List<Object> mpims;
  List<Object> ims;
  List<Object> bots;

    write/flush after response handler has returned.
```

```
λ git cherry-pick 4f3317effea38c203c358af9cb5ce3c0e4173976
```

import (
	"fmt"

	"github.com/prometheus/procfs"
)

// GetInterfaceNetStats - get procfs.NetDevLine by interfaceName
func GetInterfaceNetStats(interf string) (procfs.NetDevLine, error) {
	proc, err := procfs.Self()
	if err != nil {
		return procfs.NetDevLine{}, err
	}
	netDev, err := proc.NetDev()
	if err != nil {
		return procfs.NetDevLine{}, err
	}
	ndl, ok := netDev[interf]
	if !ok {

   *
   * <p>Note that in GWT, class names are often obfuscated.
   *
   * @param self the object to generate the string for (typically {@code this}), used only for its
   *     class name
   * @since 18.0 (since 2.0 as {@code Objects.toStringHelper()}).
   */
  public static ToStringHelper toStringHelper(Object self) {
    return new ToStringHelper(self.getClass().getSimpleName());
  }

  /**

   * @param self a collection which might contain all elements in {@code c}
   * @param c a collection whose elements might be contained by {@code self}
   */
  static boolean containsAllImpl(Collection<?> self, Collection<?> c) {
    for (Object o : c) {
      if (!self.contains(o)) {
        return false;
      }
    }
    return true;
  }

  /** An implementation of {@link Collection#toString()}. */

import okhttp3.mockwebserver.MockResponse;
import okhttp3.mockwebserver.MockWebServer;
import okhttp3.tls.HandshakeCertificates;
import okhttp3.tls.HeldCertificate;

/**
 * Create an HTTPS server with a self-signed certificate that OkHttp trusts.
 */
public class HttpsServer {
  public void run() throws Exception {
    HeldCertificate localhostCertificate = new HeldCertificate.Builder()

```Python
something(some_argument, some_keyword_argument="foo")
```

这就是 "可调用对象"。

## 类作为依赖项

您可能会注意到，要创建一个 Python 类的实例，您可以使用相同的语法。

举个例子:

```Python
class Cat:
    def __init__(self, name: str):
        self.name = name


fluffy = Cat(name="Mr Fluffy")
```

在这个例子中, `fluffy` 是一个 `Cat` 类的实例。

为了创建 `fluffy`，你调用了 `Cat` 。

所以，Python 类也是 **可调用对象**。

因此，在 **FastAPI** 中，你可以使用一个 Python 类作为一个依赖项。