private final ConcurrentMap<BuilderProblem.Severity, LongAdder> counters;
        private final ConcurrentMap<BuilderProblem.Severity, List<P>> problems;
        private final Predicate<? super P> filter;

        private static final List<BuilderProblem.Severity> REVERSED_ORDER = Arrays.stream(
                        BuilderProblem.Severity.values())
                .sorted(Comparator.reverseOrder())

                @Nonnull
                @Override
                public Collection<BuilderProblem> getProblems() {
                    return new MappedCollection<>(res.getProblems(), this::toProblem);
                }

                private BuilderProblem toProblem(ModelProblem problem) {
                    return new BuilderProblem() {
                        @Override
                        public String getSource() {

     */
    public ToolchainsBuilderException(String message, Exception e) {
        super(message, e);
    }

    public ToolchainsBuilderException(String message, ProblemCollector<BuilderProblem> problems) {
        super(message, problems);
    }

     * @param e the {@link Exception}
     */
    public SettingsBuilderException(String message, Exception e) {
        super(message, e);
    }

    public SettingsBuilderException(String message, ProblemCollector<BuilderProblem> problems) {
        super(message, problems);
    }

 * or a simple string message. In addition, a problem carries a hint about its source, e.g. the POM file that exhibits
 * the problem.
 *
 */
public interface ModelProblem extends BuilderProblem {

    /**
     * Enumeration of model versions that can be validated.
     * These versions correspond to different levels of validation that can be applied
     * during model building, based on the POM schema version.

import org.apache.maven.api.annotations.Nullable;
import org.apache.maven.api.cli.InvokerRequest;
import org.apache.maven.api.cli.Logger;
import org.apache.maven.api.cli.mvn.MavenOptions;
import org.apache.maven.api.services.BuilderProblem;
import org.apache.maven.api.services.Lookup;
import org.apache.maven.api.services.Sources;
import org.apache.maven.api.services.ToolchainsBuilder;
import org.apache.maven.api.services.ToolchainsBuilderRequest;

import org.apache.maven.api.cli.Logger;
import org.apache.maven.api.cli.cisupport.CIInfo;
import org.apache.maven.api.cli.logging.AccumulatingLogger;
import org.apache.maven.api.services.BuilderProblem;
import org.apache.maven.api.services.Lookup;
import org.apache.maven.api.services.MavenException;
import org.apache.maven.api.services.MessageBuilder;
import org.apache.maven.api.services.SettingsBuilder;