Send `data` across the data channel to the remote peer.

def send(self, data):
        """
        Send `data` across the data channel to the remote peer.
        """
        if self.readyState != 'open':
            raise InvalidStateError

        if not isinstance(data, (str, bytes)):
            raise ValueError('Cannot send unsupported data type: %s' % type(data))

        self.transport._data_channel_send(self, data)