*/
    @Nonnull
    Optional<Source> getUserToolchainsSource();

    @Nonnull
    static ToolchainsBuilderRequest build(
            @Nonnull Session session, @Nullable Source globalToolchainsSource, @Nullable Source userToolchainsSource) {
        return builder()
                .session(nonNull(session, "session cannot be null"))
                .globalToolchainsSource(globalToolchainsSource)

         * found at the given file or in the given directory.
         *
         * @since 4.0.0
         */
        @Nullable
        Path locateExistingPom(@Nonnull Path project);
    }

    @Nullable
    ModelSource resolve(@Nonnull ModelLocator modelLocator, @Nonnull String relative);

    @Nonnull
    static ModelSource fromPath(@Nonnull Path path) {

     */
    <T> boolean replace(@Nonnull Key<T> key, @Nullable T oldValue, @Nullable T newValue);

    /**
     * Gets the session data associated with the specified key.
     *
     * @param key the key for which to retrieve the session data, must not be {@code null}
     * @return the session data associated with the key or {@code null} if none
     */
    @Nullable
    <T> T get(@Nonnull Key<T> key);

    /**

                return new Exclusion() {
                    @Nullable
                    @Override
                    public String getGroupId() {
                        return exclusion.getGroupId();
                    }

                    @Nullable
                    @Override
                    public String getArtifactId() {

"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING,
BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

 */
@Experimental
@Immutable
@Provider
public interface Node {

    /**
     * @return artifact for this node
     */
    @Nullable
    Artifact getArtifact();

    /**
     * @return dependency for this node
     */
    @Nullable
    Dependency getDependency();

    /**
     * Gets the child nodes of this node.
     *
     * @return the child nodes of this node, never {@code null}
     */

import java.util.List;

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

/**
 * The result of a dependency collection request.
 *
 * @since 4.0.0
 * @see DependencyCollector#collect(DependencyCollectorRequest)
 */
@Experimental
public interface DependencyCollectorResult {

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

/**
 * Centralized class for Maven Core feature information.
 * Features configured are supposed to be final in a given maven session.
 *
 * @since 4.0.0
 */
public final class Features {

    /**
     * Name of the Maven user property to enable or disable the build/consumer POM feature.
     */

    }

    private Exclusion toExclusion(org.eclipse.aether.graph.Exclusion exclusion) {
        return new Exclusion() {
            @Nullable
            @Override
            public String getGroupId() {
                return exclusion.getGroupId();
            }

            @Nullable
            @Override
            public String getArtifactId() {
                return exclusion.getArtifactId();
            }

    boolean contains(@Nonnull Version version);

    /**
     * Returns the upper boundary of this range, or {@code null} if none.
     */
    @Nullable
    Boundary getUpperBoundary();

    /**
     * Returns the lower boundary of this range, or {@code null} if none.
     */
    @Nullable
    Boundary getLowerBoundary();

    /**
     * Returns a string representation of this version range