AbstractSlot implements Slot<T> { @Override public T listener() { return listener; } protected  AbstractSlot(Signal<T> signal, T listener, boolean once); @Override T listener(); @Override final void setEnable(boolean value); @Override final boolean isEnable(); @Override final boolean isOnce(); @Override void execute(Object[] values); @Override void remove();  }
@Test public void listener() throws Exception { assertThat(slot.listener(), is(listener)); }