async def close(self):
        """
        Close the connection.
        """
        # stop consent freshness tests
        if self._query_consent_handle and not self._query_consent_handle.done():
            self._query_consent_handle.cancel()
            try:
                await self._query_consent_handle
            except asyncio.CancelledError:
                pass

        # stop check list
        if self._check_list and not self._check_list_done:
            await self._check_list_state.put(ICE_FAILED)

        self._nominated.clear()
        for protocol in self._protocols:
            await protocol.close()
        self._protocols.clear()
        self._local_candidates.clear()
Close the connection.