gotoAndStop() for DisplayObjectContainer

I have a class called Robot that is an extension of a movieclip of a robot walking animation. It has two frames. A robotLeft frame and a robotRight frame.

Now this Robot Class has a child called robotHitbox that does all the “thinking” for the robot. but when I try to get the robotHitbox the change it’s parent’s current frame with gotoAndStop(“robotRight”) I get this error.


1061: Call to a possibly undefined method gotoAndStop through a reference with static type flash.display:DisplayObjectContainer.

Is a DisplayObjectContainer no longer a MovieClip? Am I unable to change its current frame once it has children?