old_contents: ANDROID = ("Mozilla/5.0 (Linux; Android 7.1.1; SM-J510FN Build/NMF26X) "
             "AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.87 Mobile Safari/537.36")
  CHROME = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/86.0.4240.183 Safari/537.36"
  CHROME_OS = ("Mozilla/5.0 (X11; CrOS armv7l 10718.34.0) "
               "AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.40 Safari/537.36")
  EDGE = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.163 Safari/537.36 Edg/80.0.361.111"
  FIREFOX = "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:82.0) Gecko/20100101 Firefox/82.0"
  FIREFOX_MAC = "Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:81.0) Gecko/20100101 Firefox/81.0"
  IE_6 = "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; WOW64; Trident/4.0; SLCC1)"
  IE_7 = "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0; WOW64; Trident/4.0; SLCC1)"
  IE_8 = "Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.0; WOW64; Trident/4.0; SLCC1)"
  IE_9 = "Mozilla/5.0 (MSIE 9.0; Windows NT 6.1; Trident/5.0)"
  IE_11 = "Mozilla/5.0 (Windows NT 10.0; WOW64; Trident/7.0; rv:11.0) like Gecko"
  IPAD = "Mozilla/5.0 (iPad; CPU OS 12_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/12.0 Mobile/15E148 Safari/604.1"
  IPHONE = IPHONE_6 = "Mozilla/5.0 (iPhone; CPU iPhone OS 12_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/12.0 Mobile/15E148 Safari/604.1"
  OPERA = ("Mozilla/5.0 (Windows NT 10.0; Win64; x64) "
           "AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.87 Safari/537.36 OPR/54.0.2952.64")
  SAFARI = ("Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) "
            "AppleWebKit/603.3.8 (KHTML, like Gecko) Version/10.1.2 Safari/603.3.8")
  SAFARI_8 = ("Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_4) "
              "AppleWebKit/600.7.12 (KHTML, like Gecko) Version/8.0.7 Safari/600.7.12")
  SAFARI_7 = ("Mozilla/5.0 (Macintosh; Intel Mac OS X 10_9_3) "
              "AppleWebKit/537.75.14 (KHTML, like Gecko) Version/7.0.3 Safari/7046A194A")
  WINDOWS_PHONE_8 = ("Mozilla/5.0 (compatible; MSIE 10.0; Windows Phone 8.0; "
                     "Trident/6.0; IEMobile/10.0; ARM; Touch; NOKIA; Lumia 920)")
  
new_contents: ANDROID = "Mozilla/5.0 (Linux; Android 10; SM-G960U) AppleWebKit/537.36 (KHTML, like Gecko) 87.0.4280.66 Mobile Safari/537.36"
  CHROME = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) 87.0.4280.66 Safari/537.36"
  CHROME_OS = "Mozilla/5.0 (X11; CrOS armv7l 13421.99.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.66 Safari/537.36"
  EDGE = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.66 Safari/537.36 Edg/86.0.622.68"
  FIREFOX = "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:83.0) Gecko/20100101 Firefox/83.0"
  IE_11 = "Mozilla/5.0 (Windows NT 10.0; WOW64; Trident/7.0; rv:11.0) like Gecko"
  IPAD = "Mozilla/5.0 (iPad; CPU OS 14_2 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/14.0 Mobile/15E148 Safari/604.1"
  IPHONE = "Mozilla/5.0 (iPhone; CPU iPhone OS 14_2 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/14.0 Mobile/15E148 Safari/604.1"
  OPERA = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/86.0.4240.198 Safari/537.36 OPR/72.0.3815.378"
  SAFARI = "Mozilla/5.0 (Macintosh; Intel Mac OS X 11_0_1) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/14.0 Safari/605.1.15"
  
  # Backwards compatibility
  FIREFOX_MAC = FIREFOX
  IE_6 = IE_7 = IE_8 = IE_9 = IE_11
  IPHONE_6 = IPHONE
  SAFARI_7 = SAFARI_8 = SAFARI
  WINDOWS_PHONE_8 = ANDROID
  
subject: update User-Agent's