Create MovieClip With Custom Class

/*
 Description: A function used for creating empty movie clips with subclass association.
 
 Parameters:
 c:Function - The class to associate with the the empty movie clip.
 name:String - The instance name for the empty movie clip.
 depth:Number - The depth for the empty movie clip.
 initOb:Object - Optional, object to copy properties from
 
 Returns:
 MovieClip - A reference to the newly created movie clip.
 */
MovieClip.prototype.createClassMovieClip = function(c:Function, name:String, depth:Number, initOb:Object) : MovieClip {
        var mc:MovieClip = this.createEmptyMovieClip(name, depth);
        mc.__proto__ = c.prototype;
        mc.constructor = c;
 
        if(initOb) {
                for(var prop in initOb) {
                        mc[prop] = initOb[prop];
                }
        }
 
        c.call(mc);
        return mc;
}