@abc.abstractmethod<EOL><INDENT>def apply_comment_sequencing(self, comment_search_order):<DEDENT>
pass<EOL>
Applies a comment search order to this book.

        :param comment_search_order: the comment search order
        :type comment_search_order: ``osid.commenting.CommentSearchOrder``
        :raise: ``NullArgument`` -- ``comment_search_order`` is ``null``
        :raise: ``OperationFailed`` -- unable to complete request
        :raise: ``PermissionDenied`` -- authorization failure occurred
        :raise: ``Unsupported`` -- ``comment_search_order`` not of this service

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