/**
* Updates the graph sheet's dimensions according to the set margin.
*/
private void updateDimensions() {
Vector topLeftVector = new Vector(originalTopLeft);
topLeftVector.sub(margin, margin, 0);
topLeft = new PointImpl(topLeftVector);
Vector bottomRightVector = new Vector(originalBottomRight);
bottomRightVector.add(margin, margin, 0);
bottomRight = new PointImpl(bottomRightVector);