objectRuntimeType function Null safety
Framework code should use this method in favor of calling toString on
Object.runtimeType.
Calling toString on a runtime type is a non-trivial operation that can
negatively impact performance. If asserts are enabled, this method will
return object.runtimeType.toString(); otherwise, it will return the
optimizedValue, which must be a simple constant string.
Implementation
String objectRuntimeType(Object? object, String optimizedValue) {
  assert(() {
    optimizedValue = object.runtimeType.toString();
    return true;
  }());
  return optimizedValue;
}