public function setAncestorId($id, $relatedId) {
		// find
		$model = $this->get($id);

		if ($model === null) {
			return new NotFound(['message' => 'Lineage not found.']);
		}

		// update
		if ($this->doSetAncestorId($model, $relatedId)) {
			$this->dispatch(LineageEvent::PRE_ANCESTOR_UPDATE, $model);
			$this->dispatch(LineageEvent::PRE_SAVE, $model);
			$model->save();
			$this->dispatch(LineageEvent::POST_ANCESTOR_UPDATE, $model);
			$this->dispatch(LineageEvent::POST_SAVE, $model);

			return Updated(['model' => $model]);
		}

		return NotUpdated(['model' => $model]);
	}