/// note

This is supported since FastAPI version `0.115.0`. 🤓

///

## Header Parameters with a Pydantic Model

Declare the **header parameters** that you need in a **Pydantic model**, and then declare the parameter as `Header`:

//// tab | Python 3.10+

```Python hl_lines="9-14  18"
{!> ../../docs_src/header_param_models/tutorial001_an_py310.py!}
```

////

    }

    // Write the length. This takes 1 byte if length is less than 128.
    val length = content.size
    if (length < 128) {
      sink.writeByte(length.toInt())
    } else {
      // count how many bytes we'll need to express the length.
      val lengthBitCount = 64 - java.lang.Long.numberOfLeadingZeros(length)
      val lengthByteCount = (lengthBitCount + 7) / 8
      sink.writeByte(0b1000_0000 or lengthByteCount)

///

<img src="/img/tutorial/path-operation-configuration/image03.png">

## Deprecate a *path operation*

If you need to mark a *path operation* as <abbr title="obsolete, recommended not to use it">deprecated</abbr>, but without removing it, pass the parameter `deprecated`:

```Python hl_lines="16"

	for {
		if !globalCallhomeConfig.Enabled() {
			// Stop the processing as callhome got disabled
			return false
		}

		select {
		case <-ctx.Done():
			// indicates that we do not need to run callhome anymore
			return false
		case <-callhomeTimer.C:
			if !globalCallhomeConfig.Enabled() {
				// Stop the processing as callhome got disabled
				return false
			}

			performCallhome(ctx)

#   destroys some temporary bazel data and causes longer builds.
#
#   You will need the NVIDIA Container Toolkit for GPU testing:
#   https://github.com/NVIDIA/nvidia-container-toolkit
#
#   Note: if you interrupt a bazel command on docker (ctrl-c), you
#   will need to run `docker exec tf pkill bazel` to quit bazel.
#
#   Note: new files created from the container are owned by "root".

 * For more information about the usage tag, have a look to:
 * <a href="https://maven.apache.org/developers/mojo-api-specification.html">
 * https://maven.apache.org/developers/mojo-api-specification.html</a>
 *
 * TODO is there a need for the delegation of MavenMojoDescriptor to this?
 * Why not just extend ComponentDescriptor here?
 */
public class MojoDescriptor extends ComponentDescriptor<Mojo> implements Cloneable {
    /** The Plexus component type */

		//   into memory, any mutation on xl.meta subsequently is
		//   inconsequential to the overall read operation.
		// - xl.meta metadata is still verified for quorum under lock()
		//   however writing the response doesn't need to serialize
		//   concurrent writers
		unlockOnDefer = true
		nsUnlocker = func() { lock.RUnlock(lkctx) }
	}

	fi, metaArr, onlineDisks, err := er.getObjectFileInfo(ctx, bucket, object, opts, true)

			isExplicitlyEnabled = cfgEnableVal != ""
		)

		var enabled bool
		if isExplicitlyEnabled {
			enabled, err = config.ParseBool(cfgEnableVal)
			if err != nil {
				return c, err
			}
			// No need to continue loading if the config is not enabled.
			if !enabled {
				continue
			}
		}

		p := newProviderCfgFromConfig(getCfgVal)
		configURL := getCfgVal(ConfigURL)

		if !isExplicitlyEnabled {

    override fun read(
      sink: Buffer,
      byteCount: Long,
    ): Long {
      check(fileOperator != null)

      val source: Int =
        synchronized(this@Relay) {
          // We need new data from upstream.
          while (true) {
            val upstreamPos = ******@****.***amPos
            if (sourcePos != upstreamPos) break

            // No more data upstream. We're done.

pkg crypto/ed25519, func Sign(PrivateKey, []uint8) []uint8
pkg crypto/ed25519, func Verify(PublicKey, []uint8, []uint8) bool
pkg crypto/ed25519, method (PrivateKey) Public() crypto.PublicKey
pkg crypto/ed25519, method (PrivateKey) Seed() []uint8
pkg crypto/ed25519, method (PrivateKey) Sign(io.Reader, []uint8, crypto.SignerOpts) ([]uint8, error)
pkg crypto/ed25519, type PrivateKey []uint8
pkg crypto/ed25519, type PublicKey []uint8