return new Builder<>();
  }

  /**
   * A builder for creating immutable class-to-instance maps. Example:
   *
   * <pre>{@code
   * static final ImmutableClassToInstanceMap<Handler> HANDLERS =
   *     new ImmutableClassToInstanceMap.Builder<Handler>()
   *         .put(FooHandler.class, new FooHandler())
   *         .put(BarHandler.class, new SubBarHandler())
   *         .put(Handler.class, new QuuxHandler())

        }
      };

  @Override
  protected final void tearDown() {
    tearDownStack.runTearDown();
    assertNull(
        "exceptions should not be propagated to uncaught exception handlers",
        thrownByExecutionThread);
  }

  public void testServiceStartStop() throws Exception {
    WaitOnRunService service = new WaitOnRunService();
    assertFalse(service.startUpCalled);

    return new Builder<>();
  }

  /**
   * A builder for creating immutable class-to-instance maps. Example:
   *
   * <pre>{@code
   * static final ImmutableClassToInstanceMap<Handler> HANDLERS =
   *     new ImmutableClassToInstanceMap.Builder<Handler>()
   *         .put(FooHandler.class, new FooHandler())
   *         .put(BarHandler.class, new SubBarHandler())
   *         .put(Handler.class, new QuuxHandler())

    return new Builder<>();
  }

  /**
   * A builder for creating immutable type-to-instance maps. Example:
   *
   * <pre>{@code
   * static final ImmutableTypeToInstanceMap<Handler<?>> HANDLERS =
   *     ImmutableTypeToInstanceMap.<Handler<?>>builder()
   *         .put(new TypeToken<Handler<Foo>>() {}, new FooHandler())
   *         .put(new TypeToken<Handler<Bar>>() {}, new SubBarHandler())
   *         .build();

        }
      };

  @Override
  protected final void tearDown() {
    tearDownStack.runTearDown();
    assertNull(
        "exceptions should not be propagated to uncaught exception handlers",
        thrownByExecutionThread);
  }

  public void testServiceStartStop() throws Exception {
    WaitOnRunService service = new WaitOnRunService();
    assertFalse(service.startUpCalled);