/**
     * Select all toolchains available in user settings matching the type and requirements,
     * independently from <code>maven-toolchains-plugin</code>.
     *
     * @param session the Maven session, must not be {@code null}
     * @param type the type, must not be {@code null}
     * @param requirements the requirements, may be {@code null}
     * @return the matching toolchains, never {@code null}
     * @since 3.3.0

        List<ToolchainModel> models = session.getRequest().getToolchains().get(type);

        return selectToolchains(models, type, requirements);
    }

    private List<Toolchain> selectToolchains(
            List<ToolchainModel> models, String type, Map<String, String> requirements) {
        List<Toolchain> toolchains = new ArrayList<>();

    /**
     * Let the toolchain decide if it matches requirements defined
     * in the toolchain plugin configuration.
     *
     * @param requirements key value pair, may not be {@code null}
     * @return {@code true} if the requirements match, otherwise {@code false}
     */
    boolean matchesRequirements(Map<String, String> requirements);

    /**
     * Let the toolchain decide if it matches requirements defined
     * in the toolchain plugin configuration.
     * @param requirements Map<String, String> key value pair, may not be {@code null}
     * @return {@code true} if the requirements match, otherwise {@code false}
     */
    boolean matchesRequirements(Map<String, String> requirements);

    /**
     *

    public List<Toolchain> getToolchains(Session session, String type, Map<String, String> requirements)
            throws ToolchainManagerException {
        MavenSession s = InternalMavenSession.from(session).getMavenSession();
        List<org.apache.maven.toolchain.Toolchain> toolchains =
                toolchainManagerPrivate.getToolchains(s, type, requirements);
        return new MappedList<>(toolchains, this::toToolchain);
    }

        provides.put(type, matcher);
    }

    @Override
    public boolean matchesRequirements(Map<String, String> requirements) {
        for (Map.Entry<String, String> requirement : requirements.entrySet()) {
            String key = requirement.getKey();

            RequirementMatcher matcher = provides.get(key);

            if (matcher == null) {

    <p>The <a href="/plugins/maven-toolchains-plugin/">toolchains-plugin</a> can read available toolchains on the user's computer
    and match them against the toolchain requirements of the project (as configured in {@code pom.xml}):
    if match is found, the toolchain instance is made available to other Maven plugins.</p>

 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.maven.classrealm;

import java.util.List;
import java.util.Map;

/**
 * Describes the requirements for a new class realm.
 *
 */
public interface ClassRealmRequest {

    /**
     * The type of a class realm.
     */
    enum RealmType {
        /**

    }

    private List<MavenProject> getSchedulableNewProcesses(MavenProject finishedProject) {
        List<MavenProject> result = new ArrayList<>();
        // schedule dependent projects, if all of their requirements are met
        for (MavenProject dependentProject : projectDependencyGraph.getDownstreamProjects(finishedProject, false)) {
            final List<MavenProject> upstreamProjects =

 */
package org.apache.maven.plugin.descriptor;

/**
 * Describes a component requirement.
 *
 */
public class Requirement implements Cloneable {
    private final String role;

    private final String roleHint;

    public Requirement(String role) {
        this.role = role;
        this.roleHint = null;
    }

    public Requirement(String role, String roleHint) {
        this.role = role;