code: def process_request(self, request):
          
  
          request.auth_type = None
          
          http_authorization = request.META.get("HTTP_AUTHORIZATION", None)
          
          if not http_authorization:
              return
          
          auth = http_authorization.split()
          
          self.auth_type = auth[0].lower()
          self.auth_value = " ".join(auth[1:]).strip()
          
          request.auth_type = self.auth_type
          
          self.validate_auth_type()
          
          if not self.handler_name:
              raise Exception("There is no handler defined for this authentication type.")
          
          self.load_handler()
          
          response = self.handler.validate(self.auth_value, request)
          
          if response is not None:
              return response
          
          request.access_token = self.handler.access_token(self.auth_value, request)
          request.user = self.handler.authenticate(self.auth_value, request)
docs: Try to authenticate the user based on any given tokens that have been provided
          to the request object.  This will try to detect the authentication type and assign
          the detected User object to the `request.user` variable, similar to the standard
          Django authentication.