Computes the value for the Sec-WebSocket-Accept header,
        given the value for Sec-WebSocket-Key.

def compute_accept_value(key: Union[str, bytes]) -> str:
        """Computes the value for the Sec-WebSocket-Accept header,
        given the value for Sec-WebSocket-Key.
        """
        sha1 = hashlib.sha1()
        sha1.update(utf8(key))
        sha1.update(b"258EAFA5-E914-47DA-95CA-C5AB0DC85B11")  # Magic value
        return native_str(base64.b64encode(sha1.digest()))