# Header Parameter Models

If you have a group of related **header parameters**, you can create a **Pydantic model** to declare them.

This would allow you to **re-use the model** in **multiple places** and also to declare validations and metadata for all the parameters at once. 😎

/// note

This is supported since FastAPI version `0.115.0`. 🤓

///

## Header Parameters with a Pydantic Model

  }

  private void assertCleared() {
    assertEquals(0, multimap().size());
    assertEmpty(multimap());
    assertEquals(multimap(), getSubjectGenerator().create());
    assertEmpty(multimap().entries());
    assertEmpty(multimap().asMap());
    assertEmpty(multimap().keySet());
    assertEmpty(multimap().keys());
    assertEmpty(multimap().values());

    Map<String, String> requestBody = new LinkedHashMap<>();
    requestBody.put("longUrl", "https://publicobject.com/2014/12/04/html-formatting-javadocs/");
    RequestBody jsonRequestBody = RequestBody.create(
        mapJsonAdapter.toJson(requestBody), MEDIA_TYPE_JSON);
    Request request = new Request.Builder()
        .url("https://www.googleapis.com/urlshortener/v1/url?key=" + GOOGLE_API_KEY)
        .post(jsonRequestBody)

  public void testEquals_containingNull() {
    ArrayList<E> elements = new ArrayList<>(getSampleElements());
    elements.set(elements.size() / 2, null);
    collection = getSubjectGenerator().create(elements.toArray());
    List<E> other = new ArrayList<>(getSampleElements());
    assertFalse(
        "Two Lists should not be equal if exactly one of them has null at a given index.",
        getList().equals(other));
  }

- Fixed a bug in the TopologyManager. Previously, the TopologyManager would only guarantee alignment if container creation was serialized in some way. Alignment is now guaranteed under all scenarios of container creation. ([#87759](https://github.com/kubernetes/kubernetes/pull/87759), [@klueska](https://github.com/klueska)) [SIG Node]

   ** Build up a raw model by re-reading the file and enriching it based on information available in the reactor. Some features:

      *** Resolve version of versionless parents based on relativePath (including ci-friendly versions)

      *** Resolve version of versionless dependencies that are part of the reactor

   []

  public void testSubList_originalListSetAffectsSubList() {
    List<E> subList = getList().subList(0, 1);
    getList().set(0, e3());
    assertEquals(
        "A set() call to a list after a sublist has been created "
            + "should be reflected in the sublist",
        singletonList(e3()),
        subList);
  }

  @ListFeature.Require(SUPPORTS_REMOVE_WITH_INDEX)
  @CollectionSize.Require(absent = {ZERO, ONE})

  public void testSubList_originalListSetAffectsSubList() {
    List<E> subList = getList().subList(0, 1);
    getList().set(0, e3());
    assertEquals(
        "A set() call to a list after a sublist has been created "
            + "should be reflected in the sublist",
        singletonList(e3()),
        subList);
  }

  @ListFeature.Require(SUPPORTS_REMOVE_WITH_INDEX)
  @CollectionSize.Require(absent = {ZERO, ONE})

func (sys *LifecycleSys) Get(bucketName string) (lc *lifecycle.Lifecycle, err error) {
	lc, _, err = globalBucketMetadataSys.GetLifecycleConfig(bucketName)
	return lc, err
}

// NewLifecycleSys - creates new lifecycle system.
func NewLifecycleSys() *LifecycleSys {
	return &LifecycleSys{}
}

	prometheus.MustRegister(newMinioCollector())
	prometheus.MustRegister(minioVersionInfo)
}

// newMinioCollector describes the collector
// and returns reference of minioCollector
// It creates the Prometheus Description which is used
// to define metric and  help string
func newMinioCollector() *minioCollector {
	return &minioCollector{