@abc.abstractmethod<EOL><INDENT>def get_composition_form_for_update(self, composition_id):<DEDENT>
return<EOL>
Gets the composition form for updating an existing composition.

        A new composition form should be requested for each update
        transaction.

        :param composition_id: the ``Id`` of the ``Composition``
        :type composition_id: ``osid.id.Id``
        :return: the composition form
        :rtype: ``osid.repository.CompositionForm``
        :raise: ``NotFound`` -- ``composition_id`` is not found
        :raise: ``NullArgument`` -- ``composition_id`` is ``null``
        :raise: ``OperationFailed`` -- unable to complete request
        :raise: ``PermissionDenied`` -- authorization failure

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