Initialize metaconfig for provisioning self.

def _metaconfigure(self, argv=None):
        """Initialize metaconfig for provisioning self."""
        metaconfig = self._get_metaconfig_class()
        if not metaconfig:
            return
        if self.__class__ is metaconfig:
            # don't get too meta
            return
        override = {
            'conflict_handler': 'resolve',
            'add_help': False,
            'prog': self._parser_kwargs.get('prog'),
        }
        self._metaconf = metaconfig(**override)
        metaparser = self._metaconf.build_parser(
            options=self._metaconf._options, permissive=False, **override)
        self._parser_kwargs.setdefault('parents', [])
        self._parser_kwargs['parents'].append(metaparser)
        self._metaconf._values = self._metaconf.load_options(
            argv=argv)
        self._metaconf.provision(self)