Get Grouped object.

def get_grouped(self, go_ntsets, go_all, gosubdag, **kws):
        """Get Grouped object."""
        kws_grpd = {k:v for k, v in kws.items() if k in Grouped.kws_dict}
        kws_grpd['go2nt'] = self._init_go2ntpresent(go_ntsets, go_all, gosubdag)
        return Grouped(gosubdag, self.godag.version, **kws_grpd)