int marginTop = this.properties.get("margin-top").getLength().mvalue();
int marginBottom = this.properties.get("margin-bottom").getLength().mvalue();
int marginLeft = this.properties.get("margin-left").getLength().mvalue();
int marginRight = this.properties.get("margin-right").getLength().mvalue();
return new Region(allocationRectangleXPosition + marginLeft,
allocationRectangleYPosition - marginTop,
allocationRectangleWidth - marginLeft -
marginRight, allocationRectangleHeight -
marginTop - marginBottom);
}