getFullTileRange(z) {
    if (!this.fullTileRanges_) {
      return this.extent_
        ? this.getTileRangeForExtentAndZ(this.extent_, z)
        : null;
    }
    return this.fullTileRanges_[z];
  }
@param {number} z Zoom level.
@return {import("../TileRange.js").default|null} Extent tile range for the specified zoom level.