[2] Make set replacement more limited in scope (annevk著, ) <https://github.com/whatwg/infra/commit/68c289660635448d9eba7238368ad310c4fbd98b>
[3] Always update a DOMTokenList (annevk著, ) <https://github.com/whatwg/dom/commit/d396872f847d63b803393092eb81843e80d566b7>
[4] Use Infra's concatenation definition (annevk著, ) <https://github.com/whatwg/dom/commit/53511b8edddd7943c5769a2dc1703cac66a1c95f>