Set the flags of this argument.

        Example: ``int_param._set_flags(a=1, b=2, c=4, d=8)``

def _set_flags(self, **flags):
        '''
        Set the flags of this argument.

        Example: ``int_param._set_flags(a=1, b=2, c=4, d=8)``
        '''
        self._flags = enum.IntEnum('_flags', flags)
        self.__dict__.update(self._flags.__members__)
        self._patch_flag_doc()