// are specific to the node & CRI configuration.  It is assumed that all
  // handlers are available on every node, and handlers of the same name are
  // equivalent on every node.
  // For example, a handler called "runc" might specify that the runc OCI
  // runtime (using native Linux containers) will be used to run the containers
  // in a pod.
  // The Handler must be lowercase, conform to the DNS Label (RFC 1123) requirements,
  // and is immutable.

        + WRAPPER_VERSION + "/maven-wrapper-" + WRAPPER_VERSION + ".jar";

    /**
     * Path to the maven-wrapper.properties file, which might contain a downloadUrl property to
     * use instead of the default one.
     */
    private static final String MAVEN_WRAPPER_PROPERTIES_PATH =
            ".mvn/wrapper/maven-wrapper.properties";

    /**

          Arrays.sort(sortedKs, comparator);
          Object[] sortedValues = new Object[size];

          // We might, somehow, be able to reorder values in-place.  But it doesn't seem like
          // there's a way around creating the separate sortedKeys array, and if we're allocating
          // one array of size n, we might as well allocate two -- to say nothing of the allocation
          // done in Arrays.sort.

<div class="screenshot">
<img src="/img/tutorial/header-param-models/image01.png">
</div>

## Forbid Extra Headers

In some special use cases (probably not very common), you might want to **restrict** the headers that you want to receive.

You can use Pydantic's model configuration to `forbid` any `extra` fields:

//// tab | Python 3.10+

```Python hl_lines="10"

		err = drc[j].RouteConfig.UnmarshalTo(r)
		if err != nil {
			return false
		}
		return name < r.Name
	})

	// In Istio 1.5, it is not enough just to sort the routes.  The virtual hosts
	// within a route might have a different order.  Sort those too.
	for i := range drc {
		route := &route.RouteConfiguration{}
		err = drc[i].RouteConfig.UnmarshalTo(route)
		if err != nil {
			return nil, err
		}

	throttle := newInstallationThrottle(in)
	for {
		throttle.Throttle(ctx)
		// if sleepWatchInstall yields without error, that means the config might have been modified in some fashion.
		// so we rerun `install`, which will update the modified config if it has fallen out of sync with
		// our desired state
		err := in.sleepWatchInstall(ctx, installedBins)
		if err != nil {

/// tip

Some editors check for unused function parameters, and show them as errors.

Using these `dependencies` in the *path operation decorator* you can make sure they are executed while avoiding editor/tooling errors.

It might also help avoid confusion for new developers that see an unused parameter in your code and could think it's unnecessary.

///

/// info

In this example we use invented custom headers `X-Key` and `X-Token`.

## Do not Separate Schemas

Now, there are some cases where you might want to have the **same schema for input and output**.

Probably the main use case for this is if you already have some autogenerated client code/SDKs and you don't want to update all the autogenerated client code/SDKs yet, you probably will want to do it at some point, but maybe not right now.

     * known-non-null type? But that particular problem might not arise here, since we're not
     * actually reading from the fields in any case in which they might be null (as proven by the
     * requireNonNull checks below). Plus, we're *already* lying here, since newHeader passes a null
     * key and value, which we pass to the superconstructor, even though the key and value type for

   | relies on the detection of a property, either matching a particular value for the property,
   | or merely testing its existence. Profiles can also be activated by JDK version prefix, where a
   | value of '1.4' might activate a profile when the build is executed on a JDK version of '1.4.2_07'.
   | Finally, the list of active profiles can be specified directly from the command line.
   |