# File lib/oauth/client/helper.rb, line 63
    def amend_user_agent_header(headers)
      @oauth_ua_string ||= "OAuth gem v#{OAuth::VERSION}"
      # Net::HTTP in 1.9 appends Ruby
      if headers['User-Agent'] && headers['User-Agent'] != 'Ruby' 
        headers['User-Agent'] += " (#{@oauth_ua_string})"
      else
        headers['User-Agent'] = @oauth_ua_string
      end
    end