def links_duplicate_on(attribute, separator)
      links.map do  |link|
        link.send(attribute).split(separator).collect do |value|
          link.dup.update(Hash[attribute, value])
        end
      end.flatten
    end
def links_duplicate_on(attribute, separator)
      links.map do  |link|
        link.send(attribute).split(separator).collect do |value|
          link.dup.update(Hash[attribute, value])
        end
      end.flatten
    end
Create multiple Links based on the attribute provided. The specified
 spearator will splitt the attribute value in distinct values and for each
 different value a Link will be created