def delay=(d)
      raise ArgumentError, 'delay must be greater than or equal to 0' if Integer(d) < 0

      @images.each { |f| f.delay = Integer(d) }
    end
def delay=(d)
      raise ArgumentError, 'delay must be greater than or equal to 0' if Integer(d) < 0

      @images.each { |f| f.delay = Integer(d) }
    end
Set same delay for all images