getImage method
Retrieve a tile as an image, based on it's coordinates and the current TileLayerOptions
Implementation
@override
ImageProvider getImage(TileCoordinates coordinates, TileLayer options) =>
FlutterMapNetworkImageProvider(
url: getTileUrl(coordinates, options),
fallbackUrl: getTileFallbackUrl(coordinates, options),
headers: headers,
httpClient: httpClient,
);