getArg<T> function
Implementation
T getArg<T>(String name, Map map) {
if (map.containsKey(name)) {
final arg = map[name];
if (arg is T) return arg;
throw Exception(
'Invalid argument type => $name '
'| Expects ${T.toString()} but got ${arg.runtimeType}',
);
} else {
throw Exception('Required argument missing => $name');
}
}