code: public void setARGB(int a, int r, int g, int b){
  		setValue(Pixel.argb(a, r, g, b));
  	}
docs: Sets an ARGB value at the position currently referenced by this Pixel.
  Each channel value is assumed to be 8bit and otherwise truncated.
  @param a alpha
  @param r red
  @param g green
  @param b blue
  @throws ArrayIndexOutOfBoundsException if this Pixel's index is not in
  range of the Img's data array.
  @see #setRGB(int, int, int)
  @see #setRGB_preserveAlpha(int, int, int)
  @see #argb(int, int, int, int)
  @see #argb_bounded(int, int, int, int)
  @see #argb_fast(int, int, int, int)
  @see #setValue(int)
  @since 1.0