* non-nullable {@code cause}, as many users expect to find one.
   */
  public ExecutionError(@CheckForNull String message, @CheckForNull Error cause) {
    super(message, cause);
  }

  /**
   * Creates a new instance with {@code null} as its detail message and the given cause. Prefer to
   * provide a non-nullable {@code cause}, as many users expect to find one.
   */

   * {@link SortedMultiset#tailMultiset}, the {@code size()} and {@code iterator()} methods of
   * {@link SortedMultiset#entrySet}, and {@link SortedMultiset#remove(Object, int)}. In many
   * situations, you may wish to override {@link SortedMultiset#elementSet} to forward to this
   * implementation or a subclass thereof.
   */
  protected class StandardElementSet extends SortedMultisets.ElementSet<E> {

import java.io.StringWriter;
import java.util.Collections;
import java.util.List;

import org.apache.maven.model.Model;

/**
 * Signals one ore more errors during model building. The model builder tries to collect as many problems as possible
 * before eventually failing to provide callers with rich error information. Use {@link #getProblems()} to query the
 * details of the failure.
 *
 */

    expected.addAll(index, elements);
    expectContents(expected);
  }

  /*
   * TODO: if we're testing a list, we could check indexOf(). (Doing it in
   * AbstractListTester isn't enough because many tests that run on lists don't
   * extends AbstractListTester.) We could also iterate over all elements to
   * verify absence
   */
  protected void expectMissing(E... elements) {
    for (E element : elements) {