ModelData resultData = new ModelData(request.getSource(), inputModel);
        String superModelVersion = inputModel.getModelVersion() != null ? inputModel.getModelVersion() : "4.0.0";
        if (!VALID_MODEL_VERSIONS.contains(superModelVersion)) {
            // Maven 3.x is always using 4.0.0 version to load the supermodel, so
            // do the same when loading a dependency.  The model validator will also

    }

    static final class DuplicateKey {
      private final Object key;
      private final Object value1;
      private final Object value2;

      DuplicateKey(Object key, Object value1, Object value2) {
        this.key = key;
        this.value1 = value1;
        this.value2 = value2;
      }

      IllegalArgumentException exception() {
        return new IllegalArgumentException(

    }
    Entry<K, ? extends V> entry1 = entryItr.next();
    K key1 = entry1.getKey();
    V value1 = entry1.getValue();
    checkEntryNotNull(key1, value1);
    // Do something that works for j2cl, where we can't call getDeclaredClass():
    EnumMap<K, V> enumMap = new EnumMap<>(singletonMap(key1, value1));
    while (entryItr.hasNext()) {
      Entry<K, ? extends V> entry = entryItr.next();
      K key = entry.getKey();

import org.apache.maven.model.v4.MavenTransformer;

/**
 */
@Named
@Singleton
public class DefaultModelValidator implements ModelValidator {

    public static final List<String> VALID_MODEL_VERSIONS =
            Collections.unmodifiableList(Arrays.asList("4.0.0", "4.1.0"));

    private static final Pattern EXPRESSION_NAME_PATTERN = Pattern.compile("\\$\\{(.+?)}");