@abc.abstractmethod<EOL><INDENT>def unassign_resource_from_group(self, resource_id, resource_group_id):<DEDENT>
pass<EOL>
Removes a ``Resource`` from a ``Resource`` group.

        :param resource_id: the ``Id`` of the ``Resource``
        :type resource_id: ``osid.id.Id``
        :param resource_group_id: the ``Id`` of the ``Repository``
        :type resource_group_id: ``osid.id.Id``
        :raise: ``NotFound`` -- ``resource_id or resource_group_id`` not found or ``resource_id`` not part of ``resource_group_id``
        :raise: ``NullArgument`` -- ``resource_id or resource_group_id is null``
        :raise: ``OperationFailed`` -- unable to complete request
        :raise: ``PermissionDenied`` -- authorization failure

        *compliance: mandatory -- This method must be implemented.*