#3989 raises the issue that `@Subscribe` methods with primitive parameter types can be registered but they will never be called because the `post()` method takes `Object` and so autoboxes primitives.

`EventBus` should throw an exception preventing registering any `@Subscribe` methods with primitive parameters and document the restriction.
private static final String EVENT = "Hello";
  private static final String BUS_IDENTIFIER = "test-bus";
  private EventBus bus;
  @Override
  protected void setUp() throws Exception {
    super.setUp();
    bus = new EventBus(BUS_IDENTIFIER);
  }
  public void testBasicCatcherDistribution() {
    StringCatcher catcher = new StringCatcher();
    bus.register(catcher);
    bus.post(EVENT);