Method constructor

tfjs-data/src/iterators/lazy_iterator.ts:535–538

(protected upstream: LazyIterator<T>)

  private lastRead: Promise<IteratorResult<T>>;

  constructor(protected upstream: LazyIterator<T>) {
    super();
    this.lastRead = Promise.resolve({value: null, done: false});
  }

  summary() {
    return `${this.upstream.summary()} -> Serial`;