old_contents: from django.contrib.auth.models import User
  
  
  class BaseTokenAuthBackend(object):
      def authenticate(self, auth_token):
          try:
              model = self.model_class.objects.get(auth_token=auth_token)
          except self.model_class.DoesNotExist:
              return None
          return model.user
  
      def get_user(self, user_id):
             try:
                return User.objects.get(pk=user_id)
             except User.DoesNotExist:
                return None
new_contents: from django.contrib.auth.models import User
  
  
  class BaseTokenAuthBackend(object):
      def authenticate(self, auth_token):
          try:
              model = self.model_class.objects.get(auth_token=auth_token)
          except self.model_class.DoesNotExist:
              return None
          return model.user
  
      def get_user(self, user_id):
          try:
              return User.objects.get(pk=user_id)
          except User.DoesNotExist:
              return None
  
subject: Fix indentation.