'Delete config options for a domain.
Allows deletion of all options for a domain, all options in a group
or a specific option. The driver is silent if there are no options
to delete.
:param domain_id: the domain for this option
:param group: optional group option name
:param option: optional option name. If group is None, then this
parameter is ignored
The option is uniquely defined by domain_id, group and option,
irrespective of whether it is sensitive ot not.'

@abc.abstractmethod
def delete_config_options(self, domain_id, group=None, option=None):

    raise exception.NotImplemented()
