async def custom_http_exception_handler(request, exc):
    print(f"OMG! An HTTP error!: {repr(exc)}")
    return await http_exception_handler(request, exc)


@app.exception_handler(RequestValidationError)
async def validation_exception_handler(request, exc):
    print(f"OMG! The client sent invalid data!: {exc}")
    return await request_validation_exception_handler(request, exc)


@app.get("/items/{item_id}")

            ready.countDown()
            try {
              proceed.await(5, TimeUnit.SECONDS)
            } catch (e: InterruptedException) {
              throw RuntimeException(e)
            }
            chain.proceed(chain.request())
          },
        ).build()
    val t1 = makeSynchronousCall(client.newCall(newRequest("http://a/3")))
    ready.await(5, TimeUnit.SECONDS)
    executor.finishJob("http://a/2")

	if res != "8.8.8.8" {
		t.Errorf("wrong header, xff takes precedence: got %s, want: 8.8.8.8", res)
	}

	// When explicitly disabled, the XFF header is ignored and X-Real-IP is used.
	enableXFFHeader = false
	defer func() {
		enableXFFHeader = true
	}()
	res = GetSourceIP(req)
	if res != "1.1.1.1" {
		t.Errorf("wrong header, xff is disabled: got %s, want: 1.1.1.1", res)
	}

    ):
        if session is None:
            raise WebSocketException(code=status.WS_1008_POLICY_VIOLATION)
        await websocket.accept()
        while True:
            data = await websocket.receive_text()
            await websocket.send_text(f"Session cookie is: {session}")
            await websocket.send_text(f"Message text was: {data}, for item ID: {item_id}")
    ```
    """

    def __init__(
        self,

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


class GzipRequest(Request):
    async def body(self) -> bytes:
        if not hasattr(self, "_body"):
            body = await super().body()
            if "gzip" in self.headers.getlist("Content-Encoding"):
                body = gzip.decompress(body)
            self._body = body
        return self._body


class GzipRoute(APIRoute):

                available, instead of erroring out, the dependency result will be
                `None`.

                This is useful when you want to have optional authentication.

                It is also useful when you want to have authentication that can be
                provided in one of multiple optional ways (for example, in a query
                parameter or in an HTTP Bearer token).

	if err != nil {
		t.Fatalf("Stat failed: %v", err)
	}
	if !os.SameFile(fi1, fi2) {
		t.Fatalf("addr2line_test.go and %s are not same file", srcPath)
	}
	if want := "102"; srcLineNo != want {
		t.Fatalf("line number = %v; want %s", srcLineNo, want)
	}
}

// This is line 101. The test depends on that.
func TestAddr2Line(t *testing.T) {
	testenv.MustHaveGoBuild(t)

	tmpDir := t.TempDir()

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

    async def close(self) -> None:
        """
        Close the file.

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

    @classmethod
    def _validate(cls, __input_value: Any, _: Any) -> "UploadFile":

    assertFalse(service.startUpCalled);

    service.startAsync().awaitRunning();
    assertTrue(service.startUpCalled);
    assertEquals(Service.State.RUNNING, service.state());

    enterRun.await(); // to avoid stopping the service until run() is invoked

    service.stopAsync().awaitTerminated();
    assertTrue(service.shutDownCalled);
    assertEquals(Service.State.TERMINATED, service.state());

* `read(size)`：按指定数量的字节或字符（`size` (`int`)）读取文件内容；
* `seek(offset)`：移动至文件 `offset` （`int`）字节处的位置；
    * 例如，`await myfile.seek(0) ` 移动到文件开头；
    * 执行 `await myfile.read()` 后，需再次读取已读取内容时，这种方法特别好用；
* `close()`：关闭文件。

因为上述方法都是 `async` 方法，要搭配「await」使用。

例如，在 `async` *路径操作函数* 内，要用以下方式读取文件内容：

```Python
contents = await myfile.read()
```

在普通 `def` *路径操作函数*  内，则可以直接访问 `UploadFile.file`，例如：

```Python