parse (WebAgent::Cookie)

    # File lib/httpclient/cookie.rb, line 161
        def parse(str, url)
          @url = url
          cookie_elem = str.split(/;/)
          cookie_elem = join_quotedstr(cookie_elem, ';')
          first_elem = cookie_elem.shift
          if first_elem !~ /([^=]*)(\=(.*))?/
            return
            ## raise ArgumentError 'invalid cookie value'
          end
          @name = $1.strip
          @value = normalize_cookie_value($3)
          cookie_elem.each{|pair|
            key, value = pair.split(/=/)  ## value may nil
            key.strip!
            value = normalize_cookie_value(value)
            case key.downcase
            when 'domain'
              @domain = value
            when 'expires'
              @expires = nil
              begin
                @expires = Time.parse(value).gmtime() if value
              rescue ArgumentError
              end
            when 'path'
              @path = value
            when 'secure'
              @secure = true  ## value may nil, but must 'true'.
            else
              ## ignore
            end
          }
        end