ActionScript 3.0 :: AddChild Not Working With Library Clip (attachMovie Migration)?

I'm having a problem adding a library clip to my stage I can do no problem if I have a testFLV.fla that has a library clip called test_clip with the linkage set to: com.attach_clips.Clip.
 
import com.app.views.mediaDisplay;import com.attach_clips.Clip;
public class FLVTest extends Sprite {    private var _mediaDisplay:mediaDisplay;        public function FLVTest()     {        this._mediaDisplay = new mediaDisplay(null);        var clip_1_mc:Clip=new Clip();        var clip_1_mc:Clip=new Clip();        this.addChild(clip_1_mc);        clip_1_mc.x=100;    }}
 
If I use the same concept in my mediaDisplay class, the clip isn't added to the stage.   Obviously it's got to be a scope issue since 'this' in the first examplerepresents the .fla itself but in mediaDisplay this doesn't have a stage object.
 
package com.app.views {
 import flash.display.Sprite;    import com.attach_clips.Clip;        public class mediaDisplay extends Sprite     {    public function mediaDisplay(attachControls:Sprite)         {            var clip_1_mc:Clip=new Clip();            this.addChild(clip_1_mc);            clip_1_mc.x=100;         };    }}
   
how I could 'attach' test_clip to the stage from mediaDisplay?