Simple way to avoid null childs inside a DisplayObjectContainer.

SmartDisplayObjectContainer.as

package {
	
	import flash.display.DisplayObject;
	import flash.display.DisplayObjectContainer;

	/**
	*
	*	@author Rafael Rinaldi (rafaelrinaldi.com)
	*	@since 25/03/2011
	*
	*/
	
	class SmartDisplayObjectContainer extends DisplayObjectContainer {
	
		public function SmartDisplayObjectContainer() {}
		
		/** badass **/
		override public function contains( p_child : DisplayObject ) : Boolean
		{
			return p_child != null && super.contains(p_child);
		}
	
	}

}