checkNotNull<T>  function 
 
Implementation
T checkNotNull<T>(T object, [String? message]) {
  if (object == null) {
    throw ArgumentError('$message ${T.toString()}');
  } else {
    return object;
  }
}T checkNotNull<T>(T object, [String? message]) {
  if (object == null) {
    throw ArgumentError('$message ${T.toString()}');
  } else {
    return object;
  }
}