return stream().toList().iterator();
    }

    @Override
    public Stream<Lifecycle> stream() {
        return providers.stream().map(ExtensibleEnumProvider::provides).flatMap(Collection::stream);
    }

    @Override
    public Optional<Lifecycle> lookup(String id) {
        return stream().filter(lf -> Objects.equals(id, lf.id())).findAny();
    }

    @Override

    }

    public void addStep(MavenProject project, String name, BuildStep step) {
        plan.get(project).put(name, step);
    }

    public Stream<BuildStep> allSteps() {
        return plan.values().stream().flatMap(m -> m.values().stream());
    }

    public Stream<BuildStep> steps(MavenProject project) {
        return Optional.ofNullable(plan.get(project))
                .map(m -> m.values().stream())

    private const val SOCKET_BUFFER_SIZE = 256 * 1024
  }
}

class CancelModelParamProvider : SimpleProvider() {
  override fun arguments() =
    CancelTest.CancelMode.values().flatMap { c ->
      CancelTest.ConnectionType.values().map { x ->
        Pair(
          c,
          x,
        )
      }
    }

            return phases;
        }

        @Override
        public Stream<Lifecycle.Phase> allPhases() {
            return Stream.concat(Stream.of(this), phases().stream().flatMap(Lifecycle.Phase::allPhases));
        }
    }

    static class DefaultAlias implements Lifecycle.Alias {
        private final String v3Phase;
        private final String v4Phase;

                    return exception.getResults().stream()
                            .filter(projectsOutsideOfRequestScope)
                            .flatMap(projectBuildingResult -> projectBuildingResult.getProblems().stream())
                            .map(ModelProblem::getException)
                            .filter(pluginArtifactNotFoundException)

  //   sessions.size() == 0 && delete_requested == true
  //
  // TODO(b/74949947): mutations currently trigger a warning instead of a bad
  // status, this should be reverted when possible.
  tensorflow::gtl::FlatMap<TF_Session*, tensorflow::string> sessions
      TF_GUARDED_BY(mu);
  bool delete_requested TF_GUARDED_BY(mu);  // set true by TF_DeleteGraph

  // Used to link graphs contained in TF_WhileParams to the parent graph that

    }

    @Nonnull
    @Override
    public Collection<ToolchainModel> getToolchains() {
        return getMavenSession().getRequest().getToolchains().values().stream()
                .flatMap(Collection::stream)
                .map(org.apache.maven.toolchain.model.ToolchainModel::getDelegate)
                .toList();
    }

    @Nonnull
    @Override

 * relevant methods below.
 *
 * <ul>
 *   <li>This class is serializable; {@code java.util.Optional} is not.
 *   <li>{@code java.util.Optional} has the additional methods {@code ifPresent}, {@code filter},
 *       {@code flatMap}, and {@code orElseThrow}.
 *   <li>{@code java.util} offers the primitive-specialized versions {@code OptionalInt}, {@code
 *       OptionalLong} and {@code OptionalDouble}, the use of which is recommended; Guava does not

     *
     * @return a stream of all phases in this lifecycle, including nested phases
     */
    default Stream<Phase> allPhases() {
        return phases().stream().flatMap(Phase::allPhases);
    }

    /**
     * Collection of aliases for this lifecycle.
     * Aliases map Maven 3 phase names to their Maven 4 equivalents.
     *
     * @return the collection of phase aliases
     */

    public Optional<Path> getPath(@Nonnull Project project) {
        requireNonNull(project, "project" + " cannot be null");
        Optional<ProducedArtifact> mainArtifact = project.getMainArtifact();
        return mainArtifact.flatMap(artifactManager::getPath);
    }

    @Nonnull
    @Override
    public Collection<ProducedArtifact> getAttachedArtifacts(@Nonnull Project project) {
        requireNonNull(project, "project" + " cannot be null");