/**
 * Creates a [Provider] that returns `true` when this [Provider] has a value
 * and `false` otherwise. The returned [Provider] always has a value.
 * @see Provider.isPresent
 */
private
fun <T> Provider<T>.presence(): Provider<Boolean> =
    map { true }.orElse(false)


fun Project.gradleProperty(propertyName: String) = providers.gradleProperty(propertyName)

    /**
     * Returns the root directory of the Maven invocation, if found. This is determined by the presence of a
     * {@code .mvn} directory or a POM with the root="true" property but is not always applicable (ie invocation
     * from outside a checkout).
     *
     * @return the root directory path, if present
     */
    @Nonnull
    Optional<Path> rootDirectory();

    /**

///

First, we create a `GzipRequest` class, which will overwrite the `Request.body()` method to decompress the body in the presence of an appropriate header.

If there's no `gzip` in the header, it will not try to decompress the body.

That way, the same route class can handle gzip compressed or uncompressed requests.

   */
  ALLOWS_NULL_QUERIES,
  ALLOWS_NULL_VALUES(ALLOWS_NULL_QUERIES),

  /**
   * Indicates that a collection disallows certain elements (other than {@code null}, whose validity
   * as an element is indicated by the presence or absence of {@link #ALLOWS_NULL_VALUES}). From the
   * documentation for {@link Collection}:
   *
   * <blockquote>
   *
   * "Some collection implementations have restrictions on the elements that they may contain. For

    private final ClassRealm maven4ApiRealm;

    /**
     * Patterns of artifacts provided by maven core and exported via maven api realm. These artifacts are filtered from
     * plugin and build extensions realms to avoid presence of duplicate and possibly conflicting classes on classpath.
     */
    private final Set<String> providedArtifacts;

    private final Set<String> providedArtifactsV4;

    @Inject

            "loc": [
                "query",
                "needy"
            ],
            "msg": "field required",
            "type": "value_error.missing"
        }
    ]
}
```

La présence de `needy` étant nécessaire, vous auriez besoin de l'insérer dans l'URL :

```
http://127.0.0.1:8000/items/foo-item?needy=sooooneedy
```

...ce qui fonctionnerait :

```JSON
{

				return
			}
		}

		// Apply http tracing "middleware" based on presence of flag.
		var f2 http.HandlerFunc
		if handlerFlags.Has(traceAllFlag) {
			f2 = httpTraceAll(f)
		} else {
			f2 = httpTraceHdrs(f)
		}

		// call the final handler
		f2(w, r)
	}

	// Enable compression of responses based on presence of flag.
	if !handlerFlags.Has(noGZFlag) {
		handler = gzipHandler(handler)
	}

     * (never less than 1, never more than 2), depending on project packaging.
     * <p>
     * The list's first element is ALWAYS the project POM artifact. Presence of second element in the list depends
     * solely on the project packaging.
     *
     * @see #getPackaging()
     * @see #getPomArtifact()
     * @see #getMainArtifact()

///

Cela indiquera à **FastAPI** que la présence de ce paramètre est obligatoire.

## Liste de paramètres / valeurs multiples via Query

   *
   * <p>Note that the fail-fast behavior of an iterator cannot be guaranteed as it is, generally
   * speaking, impossible to make any hard guarantees in the presence of unsynchronized concurrent
   * modification. Fail-fast iterators throw {@code ConcurrentModificationException} on a
   * best-effort basis. Therefore, it would be wrong to write a program that depended on this