Process request parameters received from the client.

        ``params`` is a list of (name, value) pairs.

        ``accepted_extensions`` is a list of previously accepted extensions.

        To accept the offer, return a 2-uple containing:

        - response parameters: a list of (name, value) pairs
        - an extension: an instance of a subclass of :class:`Extension`

        To reject the offer, raise
        :exc:`~websockets.exceptions.NegotiationError`.

def process_request_params(
        self,
        params: Sequence[ExtensionParameter],
        accepted_extensions: Sequence[Extension],
    ) -> Tuple[List[ExtensionParameter], Extension]:
        """
        Process request parameters received from the client.

        ``params`` is a list of (name, value) pairs.

        ``accepted_extensions`` is a list of previously accepted extensions.

        To accept the offer, return a 2-uple containing:

        - response parameters: a list of (name, value) pairs
        - an extension: an instance of a subclass of :class:`Extension`

        To reject the offer, raise
        :exc:`~websockets.exceptions.NegotiationError`.

        """