*     network
   * @since 23.0
   */
  Optional<E> edgeConnecting(N nodeU, N nodeV);

  /**
   * Returns the single edge that directly connects {@code endpoints} (in the order, if any,
   * specified by {@code endpoints}), if one is present, or {@code Optional.empty()} if no such edge
   * exists.
   *
   * <p>If this network is directed, the endpoints must be ordered.

    * Les valeurs de ce dictionnaire sont de type `float`.

#### `Optional`

Vous pouvez aussi utiliser `Optional` pour déclarer qu'une variable a un type, comme `str` mais qu'il est "optionnel" signifiant qu'il pourrait aussi être `None`.

{*../../docs_src/python_types/tutorial009.py hl[1,4] *}

    if (allowsNullKeys) {
      boolean unused = map.containsKey(null);
    } else {
      try {
        boolean unused2 = map.containsKey(null);
      } catch (NullPointerException optional) {
      }
    }
    assertInvariants(map);
  }

  public void testContainsValue() {
    Map<K, V> map;
    V unmappedValue;
    try {
      map = makePopulatedMap();

package org.apache.maven.cling.invoker;

import java.io.File;
import java.io.IOException;
import java.nio.file.Path;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
import java.util.Optional;
import java.util.Properties;
import java.util.ServiceLoader;
import java.util.function.Function;

import org.apache.maven.api.annotations.Nonnull;
import org.apache.maven.api.annotations.Nullable;

// +k8s:openapi-gen=true
message Quantity {
  optional string string = 1;
}

// QuantityValue makes it possible to use a Quantity as value for a command
// line parameter.
//
// +protobuf=true
// +protobuf.embed=string
// +protobuf.options.marshal=false
// +protobuf.options.(gogoproto.goproto_stringer)=false
// +k8s:deepcopy-gen=true
message QuantityValue {
  optional string string = 1;

Note: there are still some cluster roles that may need to be fixed, most likely cluster permissions
will need to move to the security component.

## Everything is Optional

Each component in the new installer is optional. Users can install the component defined in the new installer,
use the equivalent component in `istio-system`, configured with the official installer, or use a different
version or implementation.

import org.codelibs.fess.helper.SystemHelper;
import org.codelibs.fess.util.ComponentUtil;
import org.codelibs.fess.util.RenderDataUtil;
import org.dbflute.optional.OptionalEntity;
import org.dbflute.optional.OptionalThing;
import org.lastaflute.web.Execute;
import org.lastaflute.web.response.HtmlResponse;
import org.lastaflute.web.response.render.RenderData;

import org.codelibs.fess.helper.KeyMatchHelper;
import org.codelibs.fess.helper.SystemHelper;
import org.codelibs.fess.util.ComponentUtil;
import org.codelibs.fess.util.RenderDataUtil;
import org.dbflute.optional.OptionalEntity;
import org.dbflute.optional.OptionalThing;
import org.lastaflute.web.Execute;
import org.lastaflute.web.response.HtmlResponse;
import org.lastaflute.web.response.render.RenderData;

import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.util.Collection;
import java.util.LinkedHashSet;
import java.util.Set;
import java.util.SortedSet;

/**
 * Optional features of classes derived from {@code Collection}.
 *
 * @author George van den Driessche
 */
@SuppressWarnings("rawtypes") // maybe avoidable if we rework the whole package?
@GwtCompatible

};

absl::optional<std::vector<MaybeParallelTensorOwned>> ExecuteWithSpecialOps(
    const ParallelDevice& parallel_device,
    const std::string& parallel_device_name, TFE_Context* context,
    std::vector<MaybeParallelTensorUnowned> inputs, const char* operation_name,
    const TFE_OpAttrs* attributes, int expected_max_outputs,
    TF_Status* status) {
  absl::optional<std::vector<MaybeParallelTensorOwned>> result;