* well as a simple framework for helping to make sure that assertions failing in generated threads
 * cause the associated test that generated them to itself fail (which JUnit does not otherwise
 * arrange). The rules for creating such tests are:
 *
 * <ol>
 *   <li>All assertions in code running in generated threads must use the forms {@link

/**
 * Static convenience methods that serve the same purpose as Java language <a
 * href="https://docs.oracle.com/javase/8/docs/technotes/guides/language/assert.html">assertions</a>,
 * except that they are always enabled. These methods should be used instead of Java assertions
 * whenever there is a chance the check may fail "in real life". Example:
 *
 * {@snippet :
 * Bill bill = remoteService.getLastUnpaidBill();
 *

 * well as a simple framework for helping to make sure that assertions failing in generated threads
 * cause the associated test that generated them to itself fail (which JUnit does not otherwise
 * arrange). The rules for creating such tests are:
 *
 * <ol>
 *   <li>All assertions in code running in generated threads must use the forms {@link

  }

  /**
   * Asserts that {@code transformation} is vertical with the given value of {@code x}. Includes
   * assertions about all the public instance methods of {@link LinearTransformation}, including
   * assertions that {@link LinearTransformation#slope} and {@link LinearTransformation#transform}
   * throw as expected.
   */

  }

  /**
   * Asserts that {@code transformation} is vertical with the given value of {@code x}. Includes
   * assertions about all the public instance methods of {@link LinearTransformation}, including
   * assertions that {@link LinearTransformation#slope} and {@link LinearTransformation#transform}
   * throw as expected.
   */

/**
 * Static convenience methods that serve the same purpose as Java language <a
 * href="https://docs.oracle.com/javase/8/docs/technotes/guides/language/assert.html">assertions</a>,
 * except that they are always enabled. These methods should be used instead of Java assertions
 * whenever there is a chance the check may fail "in real life". Example:
 *
 * {@snippet :
 * Bill bill = remoteService.getLastUnpaidBill();
 *

      transitionStates.add(state());
      return directExecutor();
    }
  }

  // Functional tests using real thread. We only verify publicly visible state.
  // Interaction assertions are done by the single-threaded unit tests.

  private static class DefaultService extends AbstractIdleService {
    @Override
    protected void startUp() throws Exception {}

    @Override

  @Keep
  @interface TestSubtype {
    /** Suppresses the assertion on {@link TypeToken#getSubtype}. */
    boolean suppressGetSubtype() default false;

    /** Suppresses the assertion on {@link TypeToken#getSupertype}. */
    boolean suppressGetSupertype() default false;
  }

  private @Nullable Method method = null;

  /** Call this in a {@link TestSubtype} public method asserting subtype relationship. */
  final <T> T isSubtype(T sub) {

  @Keep
  @interface TestSubtype {
    /** Suppresses the assertion on {@link TypeToken#getSubtype}. */
    boolean suppressGetSubtype() default false;

    /** Suppresses the assertion on {@link TypeToken#getSupertype}. */
    boolean suppressGetSupertype() default false;
  }

  private @Nullable Method method = null;

  /** Call this in a {@link TestSubtype} public method asserting subtype relationship. */
  final <T> T isSubtype(T sub) {

      transitionStates.add(state());
      return directExecutor();
    }
  }

  // Functional tests using real thread. We only verify publicly visible state.
  // Interaction assertions are done by the single-threaded unit tests.

  private static class DefaultService extends AbstractIdleService {
    @Override
    protected void startUp() throws Exception {}

    @Override