'Creates a child xblock for the given parent.'

def _create_child(self, parent, category, display_name, publish_item=False, staff_only=False):

    child = ItemFactory.create(parent_location=parent.location, category=category, display_name=display_name, user_id=self.user.id, publish_item=publish_item)
    if staff_only:
        self._enable_staff_only(child.location)
    return modulestore().get_item(child.location)
