`moveBefore` was moved to the `ParentNode` mixin as per https://github.com/whatwg/dom/pull/1307#discussion_r1881981120 _(and was committed in https://github.com/whatwg/dom/commit/3f3e94c5beda922962dacaeb606087f57bd7f7be)_ As a result, its existence can no longer be checked on `Node.prototype` but must be checked in `Element.prototype` DiffTrain build for [313c8c55de](https://github.com/facebook/react/commit/313c8c55de39cd5f009ebb033eec1666b3daa59e)
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