}

namespace tensorflow {
namespace {
class CustomDeviceAPI : public tensorflow::CustomDevice {
 public:
  CustomDeviceAPI(TFE_Context* context, TFE_CustomDevice device, void* info,
                  string name)
      : context_(context), device_(device), info_(info), name_(name) {}

  ~CustomDeviceAPI() override { device_.delete_device(info_); }

  const string& name() override { return name_; }

        DirectoryLeaseContext context = new DirectoryLeaseContext(key, leaseState, scope);

        assertEquals(key, context.getLeaseKey());
        assertEquals(leaseState, context.getLeaseState());
        assertEquals(scope, context.getCacheScope());
        assertEquals(30000L, context.getMaxCacheAge());
        assertTrue(context.isNotificationEnabled());
        assertEquals(0, context.getNotificationFilter());
    }

            byte[] buffer = new byte[300];

            contexts[0] = new TestCreateContextResponse("CONTEXT1".getBytes(StandardCharsets.UTF_8));
            contexts[1] = new TestCreateContextResponse("CONTEXT2".getBytes(StandardCharsets.UTF_8));
            contexts[2] = new TestCreateContextResponse("CONTEXT3".getBytes(StandardCharsets.UTF_8));

            // Decode each context

        @Test
        @DisplayName("Should handle null context in array")
        void testNullContextInArray() {
            CreateContextRequest[] contexts = new CreateContextRequest[4];
            contexts[0] = new MockCreateContextRequest("FIRST");
            contexts[1] = null; // Null context
            contexts[2] = new MockCreateContextRequest("THIRD");
            contexts[3] = new MockCreateContextRequest("FOURTH");

                testEncryptionKey, testDecryptionKey);

        // When/Then - Multiple closes should be safe
        assertDoesNotThrow(() -> {
            context.close();
            context.close();
            context.close();
        });

        assertTrue(context.isClosed());
    }

## Gerenciadores de contexto { #context-managers }

### O que são "Gerenciadores de Contexto" { #what-are-context-managers }

"Gerenciadores de Contexto" são qualquer um dos objetos Python que podem ser utilizados com a declaração `with`.

## Gestionnaires de contexte { #context-managers }

### Que sont les « Context Managers » { #what-are-context-managers }

Les « Context Managers » sont des objets Python que vous pouvez utiliser dans une instruction `with`.

async def context_a(state: dict = Depends(get_state)):
    state["context_a"] = "started a"
    try:
        yield state
    finally:
        state["context_a"] = "finished a"


async def context_b(state: dict = Depends(context_a)):
    state["context_b"] = "started b"
    try:
        yield state
    finally:
        state["context_b"] = f"finished b with a: {state['context_a']}"

# 严格的 Content-Type 检查 { #strict-content-type-checking }

默认情况下，FastAPI 对 JSON 请求体使用严格的 `Content-Type` 头检查。这意味着，JSON 请求必须包含有效的 `Content-Type` 头（例如 `application/json`），其请求体才会被按 JSON 解析。

## CSRF 风险 { #csrf-risk }

此默认行为在一个非常特定的场景下，可防御一类跨站请求伪造（CSRF）攻击。

这类攻击利用了浏览器的一个事实：当请求满足以下条件时，浏览器允许脚本在不进行任何 CORS 预检的情况下直接发送请求：

- 没有 `Content-Type` 头（例如使用 `fetch()` 携带 `Blob` 作为 body）
- 且不发送任何认证凭据。

这种攻击主要在以下情况下相关：

- 应用在本地（如 `localhost`）或内网中运行

        // Then
        NegotiateContextRequest[] contexts = request.getNegotiateContexts();
        assertNotNull(contexts);
        assertEquals(2, contexts.length);

        // Verify preauth context
        assertTrue(contexts[0] instanceof PreauthIntegrityNegotiateContext);
        assertEquals(PreauthIntegrityNegotiateContext.NEGO_CTX_PREAUTH_TYPE, contexts[0].getContextType());

        // Verify encryption context