Get the event stream associated with this WVA

        Note that this event stream is shared across all users of this WVA device
        as the WVA only supports a single event stream.

        :return: a new :class:`WVAEventStream` instance

def get_event_stream(self):
        """Get the event stream associated with this WVA

        Note that this event stream is shared across all users of this WVA device
        as the WVA only supports a single event stream.

        :return: a new :class:`WVAEventStream` instance
        """
        if self._event_stream is None:
            self._event_stream = WVAEventStream(self._http_client)
        return self._event_stream