getSubdomain method
Get a subdomain value for a tile, based on it's coordinates and the current TileLayerOptions
Implementation
String getSubdomain(TileCoordinates coordinates, TileLayer options) {
if (options.subdomains.isEmpty) {
return '';
}
final index = (coordinates.x + coordinates.y) % options.subdomains.length;
return options.subdomains[index];
}