AbstractSlot implements Slot<T> { @Override public final boolean isOnce() { return once; } 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 isOnce() throws Exception { assertTrue(slot.isOnce()); slot.execute(new Object[0]); verify(signal).remove(listener); }