Subclasses use this to define the alignment of the graphic. A graphic can be rendered above its ascent. A graphic can be rendered below its descent. The GraphicAttribute object's advance is the distance from the point at which the graphic is rendered and the point where the next character or graphic is rendered. Renders this GraphicAttribute at the specified location.
Alignment can be to a particular baseline, or to the absolute top or bottom of a line.
Subclasses can override this method to provide different justification information.