def getAllConfig(self, fmt='json'):
        """
            return all element configurations as json string file.
            could be further processed by beamline.Lattice class

            :param fmt: 'json' (default) or 'dict'
        """
        for e in self.getCtrlConf(msgout=False):
            self._lattice_confdict.update(e.dumpConfig(type='simu'))
        self._lattice_confdict.update(self._lattice.dumpConfig())
        if fmt == 'json':
            return json.dumps(self._lattice_confdict)
        else:
            return self._lattice_confdict
return all element configurations as json string file.
            could be further processed by beamline.Lattice class

            :param fmt: 'json' (default) or 'dict'