def is_an_image_array(ary)
      Kernel.raise ArgumentError, "Magick::ImageList or array of Magick::Images required (#{ary.class} given)" unless ary.respond_to? :each
      ary.each { |obj| is_an_image obj }
      true
    end
def is_an_image_array(ary)
      Kernel.raise ArgumentError, "Magick::ImageList or array of Magick::Images required (#{ary.class} given)" unless ary.respond_to? :each
      ary.each { |obj| is_an_image obj }
      true
    end
Ensure array is always an array of Magick::Image objects