adjustResolution(ratio, anchor) {
    anchor = anchor && fromUserCoordinate(anchor, this.getProjection());
    this.adjustResolutionInternal(ratio, anchor);
  }
Multiply the view resolution by a ratio, optionally using an anchor. Any resolution
constraint will apply.
@param {number} ratio The ratio to apply on the view resolution.
@param {import("./coordinate.js").Coordinate} [anchor] The origin of the transformation.
@api