placement should have a set variation.\n     */\n    flipVariations: false,\n    /**\n     * @prop {Boolean} flipVariationsByContent=false\n     * The popper will switch placement variation between `-start` and `-end` when\n     * the popper element overlaps its reference boundaries.\n     *\n     * The original placement should have a set variation.\n     */\n    flipVariationsByContent: false,\n  },\n\n  /**\n   * Modifier used to make the popper flow toward the inner of the reference element.\n...