 			model = new DynamicModel(this);
 			model.validate_mouseChildren = validateMouseChildren;
 			model.validate_mouseEnabled = validateMouseEnabled;
+			model.validate_mask = validateMask;
 
 			children = new SelectableList();
 			childrenHash = new Dictionary();

			}
			return null;
		}
		
		public function get numChildren():int {
			return children.length;
		}

		protected function get inferredMinWidth():Number {
			var result:Number = 0;
			children.forEach(function(child:Layoutable, index:int, items:Array):void {
				if(!child.excludeFromLayout) {
					result = Math.max(result, child.minWidth);
				}
			});
			return result + horizontalPadding;
		}
