'Paint the line number background on the image.'

def _paint_line_number_bg(self, im):

    if (not self.line_numbers):
        return
    if (self.line_number_fg is None):
        return
    draw = ImageDraw.Draw(im)
    recth = im.size[(-1)]
    rectw = ((self.image_pad + self.line_number_width) - self.line_number_pad)
    draw.rectangle([(0, 0), (rectw, recth)], fill=self.line_number_bg)
    draw.line([(rectw, 0), (rectw, recth)], fill=self.line_number_fg)
    del draw
