FlxSignal issue

SignalTest

package ;
import flixel.util.FlxSignal;

class SignalTest {

    var signal0:FlxSignal;

    function callbackEmpty1() {}

    public function new() {
    }

    public function test() {
        signal0 = new FlxSignal();
        signal0.add(callbackEmpty1);
        if (signal0.has(callbackEmpty1)) {
            trace('PASS');
        } else {
            trace('FAIL');
        }


    }
}