def _add_subcmd_to_map(self, subcmd):
        self._subcmds_map[subcmd.name] = subcmd
        self._subcmds.append(subcmd)
Builds a dict() of valid command line arguments based on Arg()s
dataset/ETHPy150Open kbknapp/Clapp-py/clapp/clapp.py/App._add_subcmd_to_map