obtainKey method Null safety
- ImageConfiguration configuration
Converts an ImageProvider's settings plus an ImageConfiguration to a key that describes the precise image to load.
The type of the key is determined by the subclass. It is a value that unambiguously identifies the image (including its scale) that the load method will fetch. Different ImageProviders given the same constructor arguments and ImageConfiguration objects should return keys that are '==' to each other (possibly by using a class for the key that itself implements ==).
@override Future<T> obtainKey(ImageConfiguration configuration) => imageProvider.obtainKey(configuration);