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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def add_arguments(self, parser):
 """Add command arguments"""

        parser.add_argument(self._source_param, **self._source_kwargs)
        parser.add_argument('--base', '-b', action='store',
            help=   'Supply the base currency as code or a settings variable name. '
                    'The default is taken from settings CURRENCIES_BASE or SHOP_DEFAULT_CURRENCY, '
                    'or the db, otherwise USD')