unproject method
Implementation
LatLng? unproject(CustomPoint point, [double? zoom]) {
  zoom ??= _zoom;
  return options.crs.pointToLatLng(point, zoom);
}
LatLng? unproject(CustomPoint point, [double? zoom]) {
  zoom ??= _zoom;
  return options.crs.pointToLatLng(point, zoom);
}