resetExtent_() {
    if (MAX_RATIO === 0 || MIN_RATIO === 0) {
      return;
    }

    const map = this.getMap();
    const ovmap = this.ovmap_;

    const mapSize = /** @type {import("../size.js").Size} */ (map.getSize());

    const view = map.getView();
    const extent = view.calculateExtentInternal(mapSize);

    const ovview = ovmap.getView();

    // get how many times the current map overview could hold different
    // box sizes using the min and max ratio, pick the step in the middle used
    // to calculate the extent from the main map to set it to the overview map,
    const steps = Math.log(MAX_RATIO / MIN_RATIO) / Math.LN2;
    const ratio = 1 / (Math.pow(2, steps / 2) * MIN_RATIO);
    scaleFromCenter(extent, ratio);
    ovview.fitInternal(polygonFromExtent(extent));
  }
Reset the overview map extent to half calculated min and max ratio times
the extent of the main map.
@private