<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:

def extra_action(self, names, provider, action, **kwargs):
        '''
        Perform actions with block storage devices

        Example:

        .. code-block:: python

            client.extra_action(names=['myblock'], action='volume_create',
                provider='my-nova', kwargs={'voltype': 'SSD', 'size': 1000}
            )
            client.extra_action(names=['salt-net'], action='network_create',
                provider='my-nova', kwargs={'cidr': '192.168.100.0/24'}
            )
        '''
        mapper = salt.cloud.Map(self._opts_defaults())
        providers = mapper.map_providers_parallel()
        if provider in providers:
            provider += ':{0}'.format(next(six.iterkeys(providers[provider])))
        else:
            return False
        if isinstance(names, six.string_types):
            names = names.split(',')

        ret = {}
        for name in names:
            extra_ = kwargs.copy()
            extra_['name'] = name
            extra_['provider'] = provider
            extra_['profile'] = None
            extra_['action'] = action
            ret[name] = salt.utils.data.simple_types_filter(
                mapper.extras(extra_)
            )
        return ret