@abc.abstractmethod<EOL><INDENT>def remove_child_books(self, book_id):<DEDENT>
pass<EOL>
Removes all children from a book.

        :param book_id: the ``Id`` of a book
        :type book_id: ``osid.id.Id``
        :raise: ``NotFound`` -- ``book_id`` not found
        :raise: ``NullArgument`` -- ``book_id`` is ``null``
        :raise: ``OperationFailed`` -- unable to complete request
        :raise: ``PermissionDenied`` -- authorization failure

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