code: def get_repository_form_for_update(self, repository_id=None):
          
          if repository_id is None:
              raise NullArgument()
          try:
              repository = RepositoryLookupSession(proxy=self._proxy,
                                                   runtime=self._runtime).get_repository(repository_id)
          except Exception:
              raise
          repository_form = objects.RepositoryForm(repository._my_map)
          self._forms[repository_form.get_id().get_identifier()] = not UPDATED
          return repository_form
docs: Gets the repository form for updating an existing repository.
  
          A new repository form should be requested for each update
          transaction.
  
          :param repository_id: the ``Id`` of the ``Repository``
          :type repository_id: ``osid.id.Id``
          :return: the repository form
          :rtype: ``osid.repository.RepositoryForm``
          :raise: ``NotFound`` -- ``repository_id`` is not found
          :raise: ``NullArgument`` -- ``repository_id`` is ``null``
          :raise: ``OperationFailed`` -- unable to complete request
          :raise: ``PermissionDenied`` -- authorization failure
  
          *compliance: mandatory -- This method must be implemented.*