@abc.abstractmethod<EOL><INDENT>def unassign_asset_from_repository(self, asset_id, repository_id):<DEDENT>
pass<EOL>
Removes an ``Asset`` from a ``Repository``.

        :param asset_id: the ``Id`` of the ``Asset``
        :type asset_id: ``osid.id.Id``
        :param repository_id: the ``Id`` of the ``Repository``
        :type repository_id: ``osid.id.Id``
        :raise: ``NotFound`` -- ``asset_id`` or ``repository_id`` not found or ``asset_id`` not assigned to ``repository_id``
        :raise: ``NullArgument`` -- ``asset_id`` or ``repository_id`` is ``null``
        :raise: ``OperationFailed`` -- unable to complete request
        :raise: ``PermissionDenied`` -- authorization failure

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