# File lib/jpmobile/rack/mobile_carrier.rb, line 16
      def carrier(env)
        ::Jpmobile::Mobile.carriers.each do |const|
          c = ::Jpmobile::Mobile.const_get(const)
          if c.check_carrier(env)
            res = ::Rack::Request.new(env)
            return c.new(env, res)
          end
        end

        nil
      end