code: @Pure
  	public double toCenterY(double y) {
  		final double adjustedY = this.invertY.get() ? -y : y;
  		return adjustedY + this.translationY.get();
  	}
docs: Change the coordinate system of {@code y} from the
  global document coordinate system to the "centered" graphical coordinate system.
  
  @param y the y document coordinate to convert.
  @return the x coordinate in the "centered" graphical coordinate system.