* `path` - 📁 📁 🎏.
* `headers` - 🙆 🛃 🎚 🔌, 📖.
* `media_type` - 🎻 🤝 📻 🆎. 🚥 🔢, 📁 ⚖️ ➡ 🔜 ⚙️ 🔑 📻 🆎.
* `filename` - 🚥 ⚒, 👉 🔜 🔌 📨 `Content-Disposition`.

📁 📨 🔜 🔌 ☑ `Content-Length`, `Last-Modified` & `ETag` 🎚.

```Python hl_lines="2  10"
{!../../docs_src/custom_response/tutorial009.py!}
```

👆 💪 ⚙️ `response_class` 🔢:

```Python hl_lines="2  8  10"

        DefaultModelBuildingRequest request = new DefaultModelBuildingRequest();
        request.setModelSource(new FileModelSource(new File(
                getClass().getResource("/poms/depmgmt/root-dep-last.xml").getFile())));
        request.setModelResolver(new BaseModelResolver() {
            public ModelSource resolveModel(org.apache.maven.model.Dependency dependency)
                    throws UnresolvableModelException {

与其他响应类型相比，接受不同的参数集进行实例化：

* `path` - 要流式传输的文件的文件路径。
* `headers` - 任何自定义响应头，传入字典类型。
* `media_type` - 给出媒体类型的字符串。如果未设置，则文件名或路径将用于推断媒体类型。
* `filename` - 如果给出，它将包含在响应的 `Content-Disposition` 中。

文件响应将包含适当的 `Content-Length`，`Last-Modified` 和 `ETag` 的响应头。

```Python hl_lines="2  10"
{!../../docs_src/custom_response/tutorial009.py!}
```

## 额外文档

/// tip

Prefer to use the `Annotated` version if possible.

///

```Python
commons: CommonQueryParams = Depends(CommonQueryParams)
```

////

The last `CommonQueryParams`, in:

```Python
... Depends(CommonQueryParams)
```

...is what **FastAPI** will actually use to know what is the dependency.

  val streamHandler: StreamHandler?

  val inTunnel: Boolean
  val informationalResponses: List<MockResponse>

  val throttleBytesPerPeriod: Long
  val throttlePeriodNanos: Long

  val socketPolicy: SocketPolicy

  val bodyDelayNanos: Long
  val headersDelayNanos: Long

  val pushPromises: List<PushPromise>

  val settings: Settings

  @JvmOverloads
  constructor(
    code: Int = 200,

          "Did you forget to close a response body?"
      Platform.get().logCloseableLeak(message, callReference.callStackTrace)

      references.removeAt(i)

      // If this was the last allocation, the connection is eligible for immediate eviction.
      if (references.isEmpty()) {
        connection.idleAtNs = now - keepAliveDurationNs
        return 0
      }
    }

    return references.size

	// Is MINIO_SYNC_BOOT set?
	globalEnableSyncBoot bool

	// Contains NIC interface name used for internode communication
	globalInternodeInterface     string
	globalInternodeInterfaceOnce sync.Once

	// Set last client perf extra time (get lock, and validate)
	globalLastClientPerfExtraTime int64

	// Captures all batch jobs metrics globally
	globalBatchJobsMetrics batchJobMetrics

			if p.buf[bufIdx] == nil {
				// Reading first time on this disk, hence the buffer needs to be allocated.
				// Subsequent reads will reuse this buffer.
				p.buf[bufIdx] = make([]byte, p.shardSize)
			}
			// For the last shard, the shardsize might be less than previous shard sizes.
			// Hence the following statement ensures that the buffer size is reset to the right size.
			p.buf[bufIdx] = p.buf[bufIdx][:p.shardSize]

   * @param element the element to append to the end
   * @return an array whose size is one larger than {@code array}, with the same contents as {@code
   *     array}, plus {@code element} occupying the last position.
   */
  public static <T extends @Nullable Object> T[] concat(T[] array, @ParametricNullness T element) {
    T[] result = Arrays.copyOf(array, array.length + 1);
    result[array.length] = element;

          assertTrue(filtered.isEmpty());
        }
      }
    }

    public void testLast() {
      for (List<Integer> contents : SAMPLE_INPUTS) {
        C filtered = filter(createUnfiltered(contents), EVEN);

        try {
          Integer first = filtered.last();
          assertFalse(filtered.isEmpty());
          assertEquals(Ordering.natural().max(filtered), first);