def config_get(self, parameter='*'):
        """Get the value of a configuration parameter(s).

        If called without argument will return all parameters.

        :raises TypeError: if parameter is not string
        """
        if not isinstance(parameter, str):
            raise TypeError("parameter must be str")
        fut = self.execute(b'CONFIG', b'GET', parameter, encoding='utf-8')
        return wait_make_dict(fut)