*
     * @see Function
     * @see Optional
     * @see HashMap#computeIfAbsent(Object, Function)
     */
    static UnaryOperator<String> memoize(UnaryOperator<String> callback) {
        Map<String, Optional<String>> cache = new HashMap<>();
        return s -> cache.computeIfAbsent(s, v -> Optional.ofNullable(callback.apply(v)))
                .orElse(null);
    }

### Additional Optional Dependencies { #additional-optional-dependencies }

There are some additional dependencies you might want to install.

Additional optional Pydantic dependencies:

* [`pydantic-settings`](https://docs.pydantic.dev/latest/usage/pydantic_settings/) - for settings management.

 */
package org.apache.maven.api.services;

import java.io.IOException;
import java.lang.module.ModuleDescriptor;
import java.nio.file.Path;
import java.util.List;
import java.util.Map;
import java.util.Optional;

import org.apache.maven.api.Dependency;
import org.apache.maven.api.DependencyScope;
import org.apache.maven.api.JavaPathType;
import org.apache.maven.api.Node;
import org.apache.maven.api.PathType;

     * class could be unloaded after the above call to `getEnumConstants` but before we call
     * `get()`, but that is vanishingly unlikely.
     */
    return ref == null ? Optional.absent() : Optional.fromNullable(enumClass.cast(ref.get()));
  }

  static String formatCompact4Digits(double value) {
    return String.format(Locale.ROOT, "%.4g", value);
  }

 * exception when queried.
 */
fun <T: Any> atMostOneOf(vararg providers: Provider<T>): Provider<T> {
    return providers.map { provider ->
        provider.map {
            Optional.of(it)
        }.orElse(
            Optional.empty<T>()
        )
    }.reduce { acc, next ->
        acc.zip(next) { left, right ->
            when {
                left.isPresent -> {

    } catch (NoSuchFieldException impossible) {
      throw new AssertionError(impossible);
    }
  }

  /**
   * Returns an optional enum constant for the given type, using {@link Enum#valueOf}. If the
   * constant does not exist, {@link Optional#absent} is returned. A common use case is for parsing
   * user input or falling back to a default enum constant. For example, {@code

 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.maven.api;

import java.util.List;
import java.util.Optional;
import java.util.function.Predicate;
import java.util.stream.Stream;

import org.apache.maven.api.annotations.Experimental;
import org.apache.maven.api.annotations.Immutable;

 * either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.util;

import org.dbflute.optional.OptionalEntity;

/**
 * Utility class for Optional operations.
 */
public class OptionalUtil {

    /**
     * Default constructor.
     */
    private OptionalUtil() {
        // Default constructor
    }

    /**

   * Predicates.notNull())}, static importing as necessary.
   *
   * <p><b>Note:</b> if {@code first} is represented as an {@link Optional}, this can be
   * accomplished with {@link Optional#or(Object) first.or(second)}. That approach also allows for
   * lazy evaluation of the fallback instance, using {@link Optional#or(Supplier)
   * first.or(supplier)}.
   *

        return delegate.getExecutionId();
    }

    @Override
    public String getGoal() {
        return delegate.getGoal();
    }

    @Override
    public Optional<XmlNode> getConfiguration() {
        return Optional.of(delegate.getConfiguration()).map(Xpp3Dom::getDom);
    }

    @Override
    public String toString() {
        return delegate.toString();
    }