@utilities.arguments_not_none<EOL><INDENT>def get_activities_by_assets(self, asset_ids):<DEDENT>
raise errors.Unimplemented()<EOL>
Gets the activities for the given asset.

        In plenary mode, the returned list contains all of the
        activities mapped to the asset ``Id`` or an error results if an
        ``Id`` in the supplied list is not found or inaccessible.
        Otherwise, inaccessible ``Activities`` may be omitted from the
        list and may present the elements in any order including
        returning a unique set.

        arg:    asset_ids (osid.id.IdList): ``Ids`` of ``Assets``
        return: (osid.learning.ActivityList) - list of activities
        raise:  NotFound - an ``asset_id`` not found
        raise:  NullArgument - ``asset_id_list`` is ``null``
        raise:  OperationFailed - unable to complete request
        raise:  PermissionDenied - authorization failure
        *compliance: mandatory -- This method is must be implemented.*