* the JDK {@link java.util.function.Function} class, see {@link Function}.
   */
  public static Function<Object, String> toStringFunction() {
    return ToStringFunction.INSTANCE;
  }

  // enum singleton pattern
  private enum ToStringFunction implements Function<Object, String> {
    INSTANCE;

    @Override
    public String apply(Object o) {
      checkNotNull(o); // eager for GWT.
      return o.toString();
    }

/**
 * Enumeration defining different retention periods for cached data.
 * Each value represents a specific scope and lifetime for cached items.
 *
 * @since 4.0.0
 */
@Experimental
public enum CacheRetention {
    /**
     * Data should be persisted across Maven invocations.
     * Suitable for:
     * - Dependency resolution results
     * - Compilation outputs
     * - Downloaded artifacts
     */

/**
 * Optional features of classes derived from {@code Set}.
 *
 * @author George van den Driessche
 */
@SuppressWarnings("rawtypes") // maybe avoidable if we rework the whole package?
@GwtCompatible
public enum SetFeature implements Feature<Set> {
  GENERAL_PURPOSE(CollectionFeature.GENERAL_PURPOSE);

  private final Set<Feature<? super Set>> implied;

  SetFeature(Feature<? super Set>... implied) {

 * can be used as keys.
 *
 * @since 4.0.0
 */
@Experimental
public interface ExtensibleEnum {

    /**
     * The {@code id} uniquely represents a value for this extensible enum.
     * This id should be used to compute the equality and hash code for the instance.
     *
     * @return the id
     */
    @Nonnull
    String id();

// Returns whole-file bitrot reader.
func newWholeBitrotReader(disk StorageAPI, volume, filePath string, algo BitrotAlgorithm, tillOffset int64, sum []byte) *wholeBitrotReader {
	return &wholeBitrotReader{
		disk:       disk,
		volume:     volume,
		filePath:   filePath,
		verifier:   &BitrotVerifier{algo, sum},
		tillOffset: tillOffset,
		buf:        nil,
	}

@Documented
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.TYPE)
@Inherited
public @interface After {

    /**
     * Type of pointer.
     * @see org.apache.maven.api.Lifecycle.Pointer.Type
     */
    enum Type {
        PROJECT,
        DEPENDENCIES,
        CHILDREN
    }

    /**
     * The phase name.
     */
    String phase();

    /**
     * The type of this pointer.
     */

go.sum...

             M({{"add1"}, {"add2"}}),
             {{"feed1", "add1_0:0"},
              {"feed2", "add1_0:1"},
              {"add1_0:sum:0", "add2_0:0"},
              {"feed3", "add2_0:1"},
              {"add1_0:sum:0", "add1"},
              {"add2_0:sum:0", "add2"}},
             {});
}

TEST_F(CApiFunctionTest, FromSubsetOfOps) {
  /*
   *                  |  |  |
   *                  v  v  /

import com.google.common.collect.testing.SampleElements.Enums;
import java.util.List;
import org.jspecify.annotations.NullMarked;

/**
 * An abstract {@code TestMultisetGenerator} for generating multisets containing enum values.
 *
 * @author Jared Levy
 */
@GwtCompatible
@NullMarked
public abstract class TestEnumMultisetGenerator implements TestMultisetGenerator<AnEnum> {
  @Override
  public SampleElements<AnEnum> samples() {

	}, {
		Expressions: []clause.Expression{
			clause.Eq{Column: clause.Expr{SQL: "SUM(?)", Vars: []interface{}{clause.Column{Name: "id"}}}, Value: 100},
		},
		ExpectedVars: []interface{}{100},
		Result:       "SUM(`id`) = ?",
	}, {
		Expressions: []clause.Expression{
			clause.Gte{Column: clause.Expr{SQL: "SUM(?)", Vars: []interface{}{clause.Column{Table: "users", Name: "id"}}}, Value: 100},
		},