        def origins(*args, &blk)
          @origins = args.flatten.collect do |n|
            case n
            when Regexp,
                 /^https?:\/\//,
                 'file://'        then n
            when '*'              then @public_resources = true; n
            else                  Regexp.compile("^[a-z][a-z0-9.+-]*:\\\/\\\/#{Regexp.quote(n)}")
            end
          end.flatten