def rolegroups_to_embed *rolegroups
      rolegroups.flatten.inject([]) do |res, role| 
        res << create_role(role)
        res
      end
    end
def rolegroups_to_embed *rolegroups
      rolegroups.flatten.inject([]) do |res, role| 
        res << create_role(role)
        res
      end
    end
constructor
 @param [Object] the role subject