build/lib/i18n.ts/XLF/appendHeader
class XLF:	private appendHeader(): void {
		this.appendNewLine('<?xml version="1.0" encoding="utf-8"?>', 0);
		this.appendNewLine('<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">', 0);
	}