docs: function resolutionsFromExtent(extent, opt_maxZoom, opt_tileSize) {
    const maxZoom = opt_maxZoom !== undefined ?
      opt_maxZoom : DEFAULT_MAX_ZOOM;
  
    const height = getHeight(extent);
    const width = getWidth(extent);
  
    const tileSize = toSize(opt_tileSize !== undefined ?
      opt_tileSize : DEFAULT_TILE_SIZE);
    const maxResolution = Math.max(
      width / tileSize[0], height / tileSize[1]);
  
    const length = maxZoom + 1;
    const resolutions = new Array(length);
    for (let z = 0; z < length; ++z) {
      resolutions[z] = maxResolution / Math.pow(2, z);
    }
    return resolutions;
  }