     private static var _propToAxis:Object;
     private static var _propToVirtualProp:Object;
 
-    private var propertyConstraints:*;
+    private var propertyConstraints:Dictionary;
 
     private var xAxis:SingleAxisLayout;
     private var yAxis:SingleAxisLayout;

class SetVirtualProps implements ASTNode
{
    public var object:Object;
    public var vprop0:uint;
    public var vprop1:uint;
    public var child0:ASTNode;
    public var child1:ASTNode;
    public function SetVirtualProps(object:Object,
            vprop0:uint, child0:ASTNode,
            vprop1:uint = 0, child1:ASTNode = null)
    {
        this.object = object;
        this.vprop0 = vprop0;
        this.vprop1 = vprop1;
        this.child0 = child0;
        this.child1 = child1;
    }
    public function eval():*


    private function incrementConstraint(target:Object):void
    {
        var count:int = constrainCount[target];
        constrainCount[target] = count + 1;
    }

    private function getNodeFactory(constraintType:String):NodeFactory
