def used_images
      result = content.scan(/!\[.*\]\(.*\/image\/(\d.*)\/.*\)/)
      image_ids = result.nil? ? nil : result.map{ |i| i[0].to_i }.uniq
      image_ids
    end
def used_images
      result = content.scan(/!\[.*\]\(.*\/image\/(\d.*)\/.*\)/)
      image_ids = result.nil? ? nil : result.map{ |i| i[0].to_i }.uniq
      image_ids
    end
Returns array of images used in content