@utilities.arguments_not_none<EOL><INDENT>def get_families_by_provider(self, resource_id):<DEDENT>
raise errors.Unimplemented()<EOL>
Gets a ``FamilyList`` from the given provider.

        In plenary mode, the returned list contains all known families
        or an error results. Otherwise, the returned list may contain
        only those families that are accessible through this session.

        arg:    resource_id (osid.id.Id): a resource ``Id``
        return: (osid.relationship.FamilyList) - the returned ``Family
                list``
        raise:  NullArgument - ``resource_id`` is ``null``
        raise:  OperationFailed - unable to complete request
        raise:  PermissionDenied - authorization failure
        *compliance: mandatory -- This method must be implemented.*