public String getContentOfSelectionAsImageBlock(int x, int y, int height, int width) throws DoenstFitException {
        //Outside of image
        if (x > img.getWidth() || y > img.getHeight())
            return null;

        if (height + y > img.getHeight())
            height = img.getHeight() - y;

        if (width + x > img.getWidth())
            width = img.getWidth() - x;

        ImageBlock new_block = new ImageBlock(tree, x, y, height, width);

        if (tree.fits(new_block))
            tree.addChild(new_block);
        else {
            System.err.println(new_block.getLeftUpperCornerX() + " " +
                    new_block.getLeftUpperCornerY() + " " + new_block.getWidth() + " " + new_block.getHeight());
            throw new DoenstFitException();
        }

        return "Image BlockUsedInEditingScreen";
    }