def replace( ary )
      closed!
      @leds.length.times do |ii|
        @leds[ii] = Integer(ary[ii])
      end
      self
    end
def replace( ary )
      closed!
      @leds.length.times do |ii|
        @leds[ii] = Integer(ary[ii])
      end
      self
    end
Replace the LED colors with the 24-bit RGB color values found in the `ary`.
 If the `ary` is longer than the LED string then the extra color values will
 be ignored. If the `ary` is shorter than the LED string then only the LEDS
 up to `ary.length` will be changed.

 You must call `show` for the new colors to be displayed.

 Returns this PixelPi::Leds instance.