render(mapEvent) {
    const frameState = mapEvent.frameState;
    if (!frameState) {
      this.mapProjection_ = null;
    } else {
      if (this.mapProjection_ != frameState.viewState.projection) {
        this.mapProjection_ = frameState.viewState.projection;
        this.transform_ = null;
      }
    }
  }
Update the projection. Rendering of the coordinates is done in
`handleMouseMove` and `handleMouseUp`.
@param {import("../MapEvent.js").default} mapEvent Map event.
@override