SodiumIsolateCallback<T> typedef
A callback to be executed on a separate isolate.
The callback receives the secureKeys and keyPairs that have been
transferred to it via the Sodium.runIsolated method.
Implementation
typedef SodiumIsolateCallback<T> = FutureOr<T> Function(
List<SecureKey> secureKeys,
List<KeyPair> keyPairs,
);