*/
  public double populationCovariance() {
    checkState(count() != 0);
    return sumOfProductsOfDeltas / count();
  }

  /**
   * Returns the sample covariance of the values. The count must be greater than one.
   *
   * <p>This is not guaranteed to return zero when the dataset consists of the same pair of values
   * multiple times, due to numerical errors.
   *

	defer xioutil.SafeClose(out)
	top := make([]*metaCacheEntry, len(in))
	nDone := 0
	ctxDone := ctx.Done()

	// Use simpler forwarder.
	if len(in) == 1 {
		for {
			select {
			case <-ctxDone:
				return ctx.Err()
			case v, ok := <-in[0]:
				if !ok {
					return nil
				}
				select {
				case <-ctxDone:

 *
 * @author Kevin Bourrillion
 */
@GwtCompatible
@NullMarked
public abstract class TestEnumSetGenerator implements TestSetGenerator<AnEnum> {
  @Override
  public SampleElements<AnEnum> samples() {
    return new Enums();
  }

  @Override
  public Set<AnEnum> create(Object... elements) {
    AnEnum[] array = new AnEnum[elements.length];
    int i = 0;
    for (Object e : elements) {

```shell
group_search_filter: (&(objectClass=group)(member:1.2.840.113556.1.4.1941:=%d))
user_dn_search_filter: (&(memberOf:1.2.840.113556.1.4.1941:=CN=group,DC=dc,DC=net)(sAMAccountName=%s))
```

### Sample settings

Here are some (minimal) sample settings for development or experimentation:

```shell
export MINIO_IDENTITY_LDAP_SERVER_ADDR=myldapserver.com:636
export MINIO_IDENTITY_LDAP_LOOKUP_BIND_DN='cn=admin,dc=min,dc=io'

 */
@GwtCompatible
@NullMarked
public abstract class TestStringListMultimapGenerator
    implements TestListMultimapGenerator<String, String> {

  @Override
  public SampleElements<Entry<String, String>> samples() {
    return new SampleElements<>(
        mapEntry("one", "January"),
        mapEntry("two", "February"),
        mapEntry("three", "March"),
        mapEntry("four", "April"),
        mapEntry("five", "May"));

 */
@GwtCompatible
@NullMarked
public abstract class TestStringSetMultimapGenerator
    implements TestSetMultimapGenerator<String, String> {

  @Override
  public SampleElements<Entry<String, String>> samples() {
    return new SampleElements<>(
        mapEntry("one", "January"),
        mapEntry("two", "February"),
        mapEntry("three", "March"),
        mapEntry("four", "April"),
        mapEntry("five", "May"));

        // Test successful reading of 6 bytes from the input stream.
        // The content of these bytes is not critical for this test, only that 6 bytes are read.
        byte[] data = { 0x01, 0x02, 0x03, 0x04, 0x05, 0x06 }; // Sample 6 bytes
        ByteArrayInputStream bais = new ByteArrayInputStream(data);
        SessionRetargetResponsePacket packet = new SessionRetargetResponsePacket();

        // Create a buffer large enough to hold the read bytes

 */
@GwtCompatible
@NullMarked
public abstract class TestStringListMultimapGenerator
    implements TestListMultimapGenerator<String, String> {

  @Override
  public SampleElements<Entry<String, String>> samples() {
    return new SampleElements<>(
        mapEntry("one", "January"),
        mapEntry("two", "February"),
        mapEntry("three", "March"),
        mapEntry("four", "April"),
        mapEntry("five", "May"));

        // Any PACDecodingException is acceptable for this test
        assertNotNull(e.getMessage());
    }

    @Test
    void testTooSmallPac() {
        // Test that PAC smaller than 8 bytes is rejected
        byte[] smallData = new byte[4];

        PACDecodingException e = assertThrows(PACDecodingException.class, () -> new Pac(smallData, keys));

Elle peut être une fonction asynchrone (`async def`) ou une fonction normale (`def`), **FastAPI** saura la gérer correctement.

Dans cet exemple, la fonction de tâche écrira dans un fichier (afin de simuler un envoi d'email).

L'opération d'écriture n'utilisant ni `async` ni `await`, on définit la fonction avec un `def` normal.

{* ../../docs_src/background_tasks/tutorial001.py hl[6:9] *}

## Ajouter une tâche d'arrière-plan