ask() already fails EMPTY_QUESTIONS before a request exists, so a question/requested frame with zero items is host breakage; muxFrameSchema now refuses it instead of letting an undefined first question reach the composer (review r3635427102).
ask() already fails EMPTY_QUESTIONS before a request exists, so a question/requested frame with zero items is host breakage; muxFrameSchema now refuses it instead of letting an undefined first question reach the composer (review r3635427102).