val recorded = server.takeRequest()
    assertThat(recorded.headers["Accept"]).isEqualTo("text/plain")
    assertThat(recorded.headers["Accept-Encoding"]).isEqualTo("gzip")
    assertThat(recorded.headers["Connection"]).isEqualTo("Keep-Alive")
    assertThat(recorded.headers["User-Agent"]!!).matches(Regex("okhttp/.*"))
  }

@needs_py310
@pytest.mark.parametrize(
    "path,headers,expected_status,expected_response",
    [
        ("/items", None, 200, {"User-Agent": "testclient"}),
        ("/items", {"X-Header": "notvalid"}, 200, {"User-Agent": "testclient"}),
        ("/items", {"User-Agent": "FastAPI test"}, 200, {"User-Agent": "FastAPI test"}),
    ],
)
def test(path, headers, expected_status, expected_response, client: TestClient):

      MockResponse(
        code = 302,
        headers = headersOf("Location", "/b"),
      ),
    )
    server.enqueue(MockResponse())

    val request = Request(server.url("/"))
    val call = client.newCall(request)
    val response = call.execute()

    assertThat(response.request.url.encodedPath).isEqualTo("/b")
    assertThat(response.request.headers).isEqualTo(headersOf())
  }

  var canUseHeaderValue = true
  var headerValue: String? = null

  loop@ for (i in 0 until headers.size) {
    val name = headers.name(i)
    val value = headers.value(i)

    when {
      name.equals("Cache-Control", ignoreCase = true) -> {
        if (headerValue != null) {
          // Multiple cache-control headers means we can't use the raw value.
          canUseHeaderValue = false
        } else {

		if testCase.expectedCode != actualCode {
			t.Errorf("Test %d: Expected the APIErrCode to be %d, but instead found %d", i+1, testCase.expectedCode, actualCode)
		}
	}
}

// Tests validate metadata extraction from http headers.
func TestExtractMetadataHeaders(t *testing.T) {
	testCases := []struct {
		header     http.Header
		metadata   map[string]string
		shouldFail bool
	}{
		// Validate if there a known 'content-type'.
		{

import kotlin.test.assertFailsWith
import mockwebserver3.MockResponse
import mockwebserver3.MockWebServer
import mockwebserver3.SocketPolicy.DisconnectAfterRequest
import mockwebserver3.SocketPolicy.DisconnectAtEnd
import okhttp3.Headers.Companion.headersOf
import okhttp3.MediaType.Companion.toMediaType
import okhttp3.RequestBody.Companion.toRequestBody
import okhttp3.ResponseBody.Companion.toResponseBody
import okhttp3.internal.closeQuietly

  for (int component_index = 0; component_index < tensors_.size();
       ++component_index) {
    // TODO(allenl): Add a C API for summarizing tensors. Currently custom
    // devices limiting themselves to a C API (for ABI compatibility) would need
    // to implement summarization for component tensors themselves.
    ImmediateExecutionTensorHandle* component =
        tensorflow::unwrap(tensors_[component_index].get());

def test_get_invalid_one_header_items(client: TestClient):
    response = client.get("/items/", headers={"X-Token": "invalid"})
    assert response.status_code == 400, response.text
    assert response.json() == {"detail": "X-Token header invalid"}


@needs_py39
def test_get_invalid_one_users(client: TestClient):
    response = client.get("/users/", headers={"X-Token": "invalid"})
    assert response.status_code == 400, response.text

* 创建一个允许的源列表（由字符串组成）。
* 将其作为「中间件」添加到你的 **FastAPI** 应用中。

你也可以指定后端是否允许：

* 凭证（授权 headers，Cookies 等）。
* 特定的 HTTP 方法（`POST`，`PUT`）或者使用通配符 `"*"` 允许所有方法。
* 特定的 HTTP headers 或者使用通配符 `"*"` 允许所有 headers。

```Python hl_lines="2  6-11  13-19"
{!../../docs_src/cors/tutorial001.py!}
```

默认情况下，这个 `CORSMiddleware` 实现所使用的默认参数较为保守，所以你需要显式地启用特定的源、方法或者 headers，以便浏览器能够在跨域上下文中使用它们。

支持以下参数：

	public final fun addUnsafeNonAscii (Ljava/lang/String;Ljava/lang/String;)Lokhttp3/Headers$Builder;
	public final fun build ()Lokhttp3/Headers;
	public final fun get (Ljava/lang/String;)Ljava/lang/String;
	public final fun removeAll (Ljava/lang/String;)Lokhttp3/Headers$Builder;
	public final fun set (Ljava/lang/String;Ljava/lang/String;)Lokhttp3/Headers$Builder;