# File lib/shorturl.rb, line 37
  def call(url)
    Net::HTTP.start(@hostname, @port) { |http|
      response = case @method
                 when :post: http.post(@action, "#{@field}=#{url}")
                 when :get: http.get("#{@action}?#{@field}=#{CGI.escape(url)}")
                 end
      if response.code == @code.to_s
        @block.call(response.read_body)
      end
    }
  end