message: deepClone fix
diff: @@ -85,7 +85,8 @@ export function deepClone<T>(source: T): T {
  return copy as any as T;
  }
  - if (source instanceof Object) {
  + // `instanceof Object` does not find `Object.create(null)`
  + if (typeof source === 'object' && !('prototype' in source)) {
  const copy: { [k: string]: any } = {};
  for (let k in source) {
  if (hasOwnProperty.call(source, k)) copy[k] = deepClone(source[k]);
  