getCachedData method
returns data stored in the cache for the given key
Implementation
Future<String?> getCachedData(String key) async {
try {
final file = await _fileFor(key);
if (!await file.exists()) return null;
return await file.readAsString();
} catch (e) {
ApiConfig().log('cache read failed for $key: $e');
return null;
}
}