How to override .x and .y properties of MovieClip in as3

//Note: super() method is used to invoke
//the original method you are overridding.
public override function get x():Number{
    return super.x;
}
public override function set x(xCoord:Number):void{
    super.x     = xCoord;
}

public override function get y():Number{
    return super.y;
}
public override function set y(yCoord:Number):void{
    super.y     = yCoord;
}