Perform authentication on the incoming request.

def perform_authentication(self):
        """
        Perform authentication on the incoming request.
        """

        if not self.authenticators:
            return

        request.user = None
        request.auth = None

        for authenticator in self.authenticators:
            auth_tuple = authenticator.authenticate()

            if auth_tuple:
                request.user = auth_tuple[0]
                request.auth = auth_tuple[1]
                break