public function updateWorkflowFields($fields)
    {
        $fieldDiff = $this->Workflow()->getTargetDiff();

        foreach ($fieldDiff as $field) {
            $display = ReadonlyField::create(
                'workflow-' . $field->Name,
                $field->Title,
                DBField::create_field('HTMLText', $field->Diff)
            )
                ->addExtraClass('workflow-field-diff');
            $fields->push($display);
        }

        if ($this->BaseAction()->AllowCommenting) {
            $fields->push(new TextareaField('Comment', _t('WorkflowAction.COMMENT', 'Comment')));
        }
    }