code: def hsla(self, *args):
          
          if len(args) == 4:
              h, s, l, a = args
              rgb = colorsys.hls_to_rgb(
                  int(h) / 360.0, utility.pc_or_float(l), utility.pc_or_float(s))
              color = [float(utility.convergent_round(c * 255)) for c in rgb]
              color.append(utility.pc_or_float(a))
              return "rgba(%s,%s,%s,%s)" % tuple(color)
          raise ValueError('Illegal color values')
docs: Translate hsla(...) to color string
          raises:
              ValueError
          returns:
              str