if ns1 != ns2 {
		return fmt.Errorf("Expected number of endpoints %d, seen %d", ns1, ns2)
	}

	for i, cmdLine := range s1.CmdLines {
		if cmdLine != s2.CmdLines[i] {
			return fmt.Errorf("Expected command line argument %s, seen %s", cmdLine,
				s2.CmdLines[i])
		}
	}

	if reflect.DeepEqual(s1.MinioEnv, s2.MinioEnv) {
		return nil
	}

	// Report differences in environment variables.
	var missing []string

///

The only new thing is the `callbacks=invoices_callback_router.routes` as an argument to the *path operation decorator*. We'll see what that is next.

## Documenting the callback { #documenting-the-callback }

The actual callback code will depend heavily on your own API app.

	// There are two possibilities:
	// - We use a KMS -> There must be non-empty key ID and a KMS data key.
	// - We use a K/V -> There must be no key ID and no KMS data key.
	// Otherwise, the caller has passed an invalid argument combination.
	if keyID == "" && len(kmsKey) != 0 {
		logger.CriticalIf(context.Background(), errors.New("The key ID must not be empty if a KMS data key is present"))
	}
	if keyID != "" && len(kmsKey) == 0 {

    return (graph instanceof ImmutableValueGraph)
        ? (ImmutableValueGraph<N, V>) graph
        : new ImmutableValueGraph<N, V>(graph);
  }

  /**
   * Simply returns its argument.
   *
   * @deprecated no need to use this
   */
  @InlineMe(
      replacement = "checkNotNull(graph)",
      staticImports = "com.google.common.base.Preconditions.checkNotNull")
  @Deprecated

	for _, collectorPath := range h.metricsData.collectorPaths {
		if collectorPath.isDescendantOf(path) {
			gatherer := h.metricsData.mgGatherers[collectorPath]

			// For Bucket metrics we need to set the buckets argument inside the
			// metric group, so that it will affect collection. If no buckets
			// are provided, we will not return bucket metrics.
			if bmg, ok := h.metricsData.bucketMGMap[collectorPath]; ok {

///

Now run the live server for the docs in Spanish:

<div class="termy">

```console
// Use the command "live" and pass the language code as a CLI argument
$ python ./scripts/docs.py live es

<span style="color: green;">[INFO]</span> Serving on http://127.0.0.1:8008
<span style="color: green;">[INFO]</span> Start watching changes

   * by the argument according to three criteria:
   *
   * <ol>
   *   <li>The type of the argument is the wildcard or equal to the type of this instance.
   *   <li>The subtype of the argument is the wildcard or equal to the subtype of this instance.
   *   <li>All of the parameters present in the argument are present in this instance.
   * </ol>
   *
   * <p>For example:

                        + "' has been set using a JVM system property which is deprecated. "
                        + "The property can be passed as a Maven argument or in the Maven project configuration file,"
                        + "usually located at ${session.rootDirectory}/.mvn/maven.properties.");
            }
        }
        ArrayList<Path> jars = new ArrayList<>();

		serverAddr  string
		expectedErr error
	}{
		{":54321", nil},
		{"localhost:54321", nil},
		{"0.0.0.0:9000", nil},
		{":0", nil},
		{"localhost", nil},
		{"", fmt.Errorf("invalid argument")},
		{"example.org:54321", fmt.Errorf("host in server address should be this server")},
		{":-10", fmt.Errorf("port must be between 0 to 65535")},
	}

	for _, testCase := range testCases {

	// There are two possibilities:
	// - We use a KMS -> There must be non-empty key ID and a KMS data key.
	// - We use a K/V -> There must be no key ID and no KMS data key.
	// Otherwise, the caller has passed an invalid argument combination.
	if keyID == "" && len(kmsKey) != 0 {
		logger.CriticalIf(context.Background(), errors.New("The key ID must not be empty if a KMS data key is present"))
	}
	if keyID != "" && len(kmsKey) == 0 {