Extending Java constructors with Nashorn?

[idk my name]

Let's say that there's a listener that subscribes into PacketEvent and calls my WrappedPacketEvent:

var WrappedListener = Java.extend((Java.type('net.ccbluex.liquidbounce.event.Listenable')), (Java.type('java.util.function.Consumer')), {
    handleEvents: function() { return true },
    accept: function(e) {
        e instanceof PacketEvent && LiquidBounce.INSTANCE.eventManager.callEvent(new WrappedPacketEvent(e.getPacket().wrapped)); 
    }
});

But how can I extend Event and create my own constructor that accepts Packet<?>? (Consumer?)

[idk my name]

For understanding:

The problem is in IPacket.
I want to wrap IPacket into Packet<?>, so onPacket will accept Packet<?> instead of IPacket (xversion problem, I need to write e.getPacket().wrapped instead of just e.getPacket(), that's really annoying)

[idk my name]

There's how far I got:

var WrappedListener = Java.extend((Java.type('net.ccbluex.liquidbounce.event.Listenable')), (Java.type('java.util.function.Consumer')), {
    handleEvents: function() { return module[0].state },
    accept: function(e) {
        e instanceof PacketEvent && LiquidBounce.INSTANCE.eventManager.callEvent(new WrappedPacketEvent(e.getPacket().wrapped)); 
    }
});

function WrappedPacketEvent(packet) {
    var isCancelled;

    this.isCancelled = function() isCancelled;
    this.cancelEvent = function() {
        isCancelled = true;
    }
    this.getPacket = function() packet;
}