x-template.js (10 lines):
	- line 357: // TODO: Future state here once “ifDefined” is gone.
	- line 514: // TODO: We should be able to make the following code more performant.
	- line 527: // TODO: #254: Future state where the “moveBefore” API is better-supported.
	- line 592: // TODO: Is there a way to more-performantly skip this init step? E.g., if
	- line 666: // TODO: This function is a bit of a performance bottleneck. It starts from
	- line 778: // TODO: #254: Future state when we leverage “moveBefore”.
	- line 799: // TODO: Future state — we may choose to iterate differently as an
	- line 817: // TODO: Future state — we may choose to iterate differently as an
	- line 834: // TODO: Future state — we may choose to iterate differently as an
	- line 854: // TODO: Replace with Map.prototype.getOrInsert when TC39 proposal lands.


x-element.js (1 line):
	- line 175: // TODO: #254: Uncomment once we leverage “moveBefore”.


server.js (1 line):
	- line 49: // @TODO pushState optional