src/vs/editor/contrib/linesOperations/browser/linesOperations.ts/TitleCaseAction/_modifyText
class TitleCaseAction:	protected _modifyText(text: string, wordSeparators: string): string {
		const titleBoundary = TitleCaseAction.titleBoundary.get();
		if (!titleBoundary) {
			// cannot support this
			return text;
		}
		return text
			.toLocaleLowerCase()
			.replace(titleBoundary, (b) => b.toLocaleUpperCase());
	}