code: def block_before(self):
          
          # To avoid unnecessary database queries, ignore the IP check for
          # requests for static files
          if request.path.startswith(url_for('static', filename='')):
              return
  
          # Some static files might be served from the root path (e.g.
          # favicon.ico, robots.txt, etc.). Ignore the IP check for most
          # common extensions of those files.
          ignored_extensions = ('ico', 'png', 'txt', 'xml')
          if request.path.rsplit('.', 1)[-1] in ignored_extensions:
              return
  
          ips = request.headers.getlist('X-Forwarded-For')
          if not ips:
              return
  
          # If the X-Forwarded-For header contains multiple comma-separated
          # IP addresses, we're only interested in the last one.
          ip = ips[0].strip()
          if ip[-1] == ',':
              ip = ip[:-1]
          ip = ip.rsplit(',', 1)[-1].strip()
  
          if self.matches_ip(ip):
              if self.logger is not None:
                  self.logger.info("IPBlock: matched {}, {}".format(ip, self.block_msg))
              if self.blocking_enabled:
                  return 'IP Blocked', 200
docs: Check the current request and block it if the IP address it's
          coming from is blacklisted.