* Obtain the {@link ClassRealm} used for Maven Core.
     *
     * @return the class realm of core.
     */
    @Nonnull
    ClassRealm getRealm();

    /**
     * Shorthand method to obtain the {@link ClassWorld} used for Maven Core.
     *
     * @return the class world in use.
     */
    @Nonnull
    default ClassWorld getClassWorld() {
        return getRealm().getWorld();
    }

import java.io.IOException;
import java.io.InputStream;
import java.nio.file.Path;

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

/**
 * Provides access to the contents of a source independently of the
 * backing store (e.g. file system, database, memory).
 * <p>

        final Map<Boolean, Map<String, List<ChangelogEntry.Breaking>>> breakingChangesByNotabilityByArea = entries.stream()
            .map(ChangelogEntry::getBreaking)
            .filter(Objects::nonNull)
            .sorted(comparing(ChangelogEntry.Breaking::getTitle))
            .collect(
                groupingBy(
                    ChangelogEntry.Breaking::isNotable,

     * if there are parser errors, this request may not be fully processed and should immediately be failed.
     */
    @Nonnull
    InvokerRequest parseInvocation(@Nonnull ParserRequest parserRequest);

import java.util.function.Function;
import java.util.function.UnaryOperator;

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

/**
 * The Interpolator service provides methods for variable substitution in strings and maps.

     *         {@code null}.
     */
    @Nonnull
    String getModelId();

    /**
     * Gets the applicable maven version/validation level of this problem
     * @return The version, never {@code null}.
     */
    @Nonnull
    Version getVersion();

     * @return a stream of problems with the specified severity
     */
    @Nonnull
    Stream<P> problems(BuilderProblem.Severity severity);

    /**
     * Creates an "empty" problem collector that doesn't store any problems.
     *
     * @param <P> the type of problem
     * @return an empty problem collector
     */
    @Nonnull
    static <P extends BuilderProblem> ProblemCollector<P> empty() {

     * @return {@code true} if this range contains the specified version, {@code false} otherwise
     */
    boolean contains(@Nonnull Version version);

    /**
     * {@return the string representation of this version}
     */
    @Nonnull
    @Override
    String toString();

    private CWD(Path directory) {
        this.directory = directory;
    }

    @Nonnull
    @Override
    public Path get() {
        return directory;
    }

    /**
     * Resolves against current cwd, resulting path is normalized.
     *
     * @throws NullPointerException if {@code seg} is {@code null}.
     */
    @Nonnull
    public Path resolve(String seg) {
        requireNonNull(seg, "seg");

    return ordering.<T>reverse().<@NonNull S>nullsLast();
  }

  @SuppressWarnings("unchecked") // still need the right way to explain this
  @Override
  public <S extends @Nullable T> Ordering<@Nullable S> nullsFirst() {
    return (Ordering<@Nullable S>) this;
  }

  @Override
  public <S extends @Nullable T> Ordering<@Nullable S> nullsLast() {
    return ordering.<@NonNull S>nullsLast();
  }

  @Override