[Question] about "._owner.alternate"

It seems that in react@16 every React element children contains cyclic property ._owner.alternate.alternate.alternate.alternate....

So it is easy to cause "Maximum call stack exceeded" error when developer compares props.children in deep way(like deep-equal).

This caused bugs for community libraries like react-helmet:
https://github.com/nfl/react-helmet/issues/441

I am extremely curious about:
Why React has _owner.alternate, and what it stands for?
As it is named as “_owner”, could it be better if we make “owner” not enumerable?

I tried to search source code and but still can’t find any clue.

Thanks in advance.

ファイルもテストも指定されていません。まず、要素の子と _owner.alternate チェーンを作成する React 16 のソースを追跡し、次にリンクされた react-helmet issue 441 を確認します。完了条件は、_owner.alternate が何を表すのかを文書化し、enumerable owner に関する懸念に文書化された変更が必要かどうかを解決することです。