}

  // Writer methods to enqueue frames. They'll be sent asynchronously by the writer thread.

  override fun send(text: String): Boolean = send(text.encodeUtf8(), OPCODE_TEXT)

  override fun send(bytes: ByteString): Boolean = send(bytes, OPCODE_BINARY)

  @Synchronized private fun send(
    data: ByteString,
    formatOpcode: Int,
  ): Boolean {
    // Don't send new frames after we've failed or enqueued a close frame.

You can declare a parameter in a *path operation function* or dependency function with the type `BackgroundTasks`, and then you can use it to schedule the execution of background tasks after the response is sent.

You can import it directly from `fastapi`:

```python
from fastapi import BackgroundTasks
```

                        logger.debug("Sent {} to {}.", body, url);
                    }
                } else {
                    logger.warn("Failed to send {} to {}. HTTP Status is {}. {}", body, url, response.getHttpStatusCode(),
                            response.getContentAsString());
                }
            } catch (final IOException e) {
                logger.warn("Failed to send {} to {}.", body, url, e);
            }

        // Verify interactions
        verify(tree, times(1)).send(isA(Trans2FindFirst2.class), any(Trans2FindFirst2Response.class));
        // Verify that Trans2FindNext2 was sent twice for fetching more entries
        verify(tree, times(2)).send(isA(Trans2FindNext2.class), any(Trans2FindFirst2Response.class));

        // Close should have sent FindClose2 exactly once

-rwxrwxrwx 1 nobody nobody           45 Apr  1 06:13 chunkdocs/metadata
226 Closing data connection, sent 75 bytes
ftp> get
(remote-file) runner/chunkdocs/metadata
(local-file) test
local: test remote: runner/chunkdocs/metadata
229 Entering Extended Passive Mode (|||37785|)
150 Data transfer starting 45 bytes
	45        3.58 KiB/s
226 Closing data connection, sent 45 bytes
45 bytes received in 00:00 (3.55 KiB/s)
...
```

{* ../../docs_src/stream_json_lines/tutorial001_py310.py ln[33:36] hl[34] *}

## 伺服器推播事件（SSE） { #server-sent-events-sse }

		return false
	}

	// If format.json is available and request sent the right disk-id, we allow the request
	return true
}

// checkID - check if the disk-id in the request corresponds to the underlying disk.
func (s *storageRESTServer) checkID(wantID string) bool {
	if s.getStorage() == nil {
		return false
	}
	if wantID == "" {
		// Request sent empty disk-id, we allow the request

You can also use `File()` with `UploadFile`, for example, to set additional metadata:

{* ../../docs_src/request_files/tutorial001_03_an_py310.py hl[9,15] *}

## Multiple File Uploads { #multiple-file-uploads }

It's possible to upload several files at the same time.

They would be associated to the same "form field" sent using "form data".

To use that, declare a list of `bytes` or `UploadFile`:

# SHA256 checksums of snapshot zip files in this directory.
# These checksums are included in the FIPS security policy
# (validation instructions sent to the lab) and MUST NOT CHANGE.
# That is, the zip files themselves must not change.
#
# It is okay to add new zip files to the list, and it is okay to
# remove zip files from the list when they are removed from
# this directory. To update this file:
#
#	go test cmd/go/internal/fips140 -update
#

Returning any error will also cancel the stream remotely.

CAREFUL: When utilizing two-way communication, it is important to ensure that the remote handler is not blocked on a send.
If the remote handler is blocked on a send, and the client is trying to send without the remote receiving,
the operation would become deadlocked if the channels are full.

### Typed handlers