def merge_from_other_cfg(self, cfg_other):
        """
        Args:
            cfg_other (CfgNode): configs to merge from.
        """
        assert (
                BASE_KEY not in cfg_other
        ), "The reserved key '{}' can only be used in files!".format(BASE_KEY)
        return super().merge_from_other_cfg(cfg_other)

        Args:
            cfg_other (CfgNode): configs to merge from.
        
fastreid/config/config.py