AbstractSlot implements Slot<T> { @Override public void remove() { signal.remove(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 remove() throws Exception { slot.remove(); verify(signal).remove(listener); }