attributesFromJson function
Implementation
Map<String, dynamic> attributesFromJson(Map<String, dynamic> json) {
if (json.length != 1) {
throw Exception("JSON element must have a single key");
}
final key = json.keys.first;
final val = json[key];
if (val is Map<String, dynamic>) {
return Map<String, dynamic>.from(val);
} else {
throw Exception("JSON element value must be an object");
}
}