interface Y {}

  static class A implements X, Y {}

  static class B implements X, Y {}

  /**
   * This test passes if the {@code concat(…).filter(…).filter(…)} statement at the end compiles.
   * That statement compiles only if {@link FluentIterable#concat concat(aIterable, bIterable)}
   * returns a {@link FluentIterable} of elements of an anonymous type whose supertypes are the <a

 * ({@code [ ]}) indicates that the range is closed on that side; a parenthesis ({@code ( )}) means
 * it is either open or unbounded. The construct {@code {x | statement}} is read "the set of all
 * <i>x</i> such that <i>statement</i>.")
 *
 * <blockquote>
 *
 * <table>
 * <caption>Range Types</caption>
 * <tr><th>Notation        <th>Definition               <th>Factory method

   *
   * <p>The use of this class is considered an implementation detail of ServiceManager and as such
   * it is excluded from {@link #servicesByState}, {@link #startupTimes}, {@link #toString} and all
   * logging statements.
   */
  private static final class NoOpService extends AbstractService {
    @Override
    protected void doStart() {
      notifyStarted();
    }

    @Override
    protected void doStop() {