*/
package okhttp3.internal.ws

import okio.Buffer
import okio.ByteString.Companion.encodeUtf8

object WebSocketProtocol {
  /** Magic value which must be appended to the key in a response header. */
  internal const val ACCEPT_MAGIC = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"

  /*
  Each frame starts with two bytes of data.

   0 1 2 3 4 5 6 7    0 1 2 3 4 5 6 7
  +-+-+-+-+-------+  +-+-------------+

### Transition Status

### Set legal hold on an object

PutObject API allows setting legal hold using `x-amz-object-lock-legal-hold` header.

```sh
aws s3api put-object --bucket testbucket --key legalhold --object-lock-legal-hold-status ON --body /etc/issue
```

    NavigableSet<E> createSubSet(SortedSet<E> sortedSet, E firstExclusive, E lastExclusive) {
      NavigableSet<E> set = (NavigableSet<E>) sortedSet;
      if (from == Bound.NO_BOUND && to == Bound.INCLUSIVE) {
        return set.headSet(lastInclusive, true);
      } else if (from == Bound.EXCLUSIVE && to == Bound.NO_BOUND) {
        return set.tailSet(firstExclusive, false);
      } else if (from == Bound.EXCLUSIVE && to == Bound.EXCLUSIVE) {

		if err != nil {
			if len(mfs) == 0 {
				writeErrorResponseJSON(r.Context(), w, toAdminAPIErr(r.Context(), err), r.URL)
				return
			}
		}

		contentType := expfmt.Negotiate(r.Header)
		w.Header().Set("Content-Type", string(contentType))

		enc := expfmt.NewEncoder(w, contentType)
		for _, mf := range mfs {
			if err := enc.Encode(mf); err != nil {
				// client may disconnect for any reasons

			if err != nil {
				err = msgp.WrapError(err)
				return
			}
		}
	}
	return
}

// EncodeMsg implements msgp.Encodable
func (z *metacache) EncodeMsg(en *msgp.Writer) (err error) {
	// map header, size 13
	// write "end"
	err = en.Append(0x8d, 0xa3, 0x65, 0x6e, 0x64)
	if err != nil {
		return
	}
	err = en.WriteTime(z.ended)
	if err != nil {
		err = msgp.WrapError(err, "ended")
		return
	}

import java.io.InputStream;
import java.io.OutputStream;
import java.io.IOException;

/**
Do not use this class. Writing to the OutputStream of this type of socket
requires leaving a 4 byte prefix for the NBT header. IOW you must call
write( buf, 4, len ). Calling write( buf, 0, len ) will generate an error.
 */

public class NbtSocket extends Socket {

    private static final int SSN_SRVC_PORT = 139;

You can add code to be run with the `request`,  before any *path operation* receives it.

And also after the `response` is generated, before returning it.

For example, you could add a custom header `X-Process-Time` containing the time in seconds that it took to process the request and generate a response:

```Python hl_lines="10  12-13"
{!../../docs_src/middleware/tutorial001.py!}
```

/// tip

	defer server.Close()

	jwt := &jwtgo.Token{
		Method: jwtgo.SigningMethodHS256,
		Claims: jwtgo.StandardClaims{
			ExpiresAt: 253428928061,
			Audience:  "76b95ae5-33ef-4283-97b7-d2a85dc2d8f4",
		},
		Header: map[string]interface{}{
			"typ": "JWT",
			"alg": jwtgo.SigningMethodHS256.Alg(),
			"kid": "76b95ae5-33ef-4283-97b7-d2a85dc2d8f4",
		},
	}

    responseBodyBytes: Matcher<Long?>?,
  ) {
    if (requestHeaderLength != null) {
      val responseHeadersEnd = listener.removeUpToEvent<RequestHeadersEnd>()
      MatcherAssert.assertThat(
        "request header length",
        responseHeadersEnd.headerLength,
        requestHeaderLength,
      )
    } else {
      assertThat(listener.recordedEventTypes())
        .doesNotContain("RequestHeadersEnd")
    }