Function flatmap

tfjs-data/src/iterators/lazy_iterator.ts:309–311

* Maps this stream through a 1-to-many transform. * * @param transform A function mapping a stream element to an array of * transformed elements. * * @returns A `DataStream` of transformed elements.

(transform: (value: T) => O[])

   * @returns A `DataStream` of transformed elements.
   */
  flatmap<O>(transform: (value: T) => O[]): LazyIterator<O> {
    return new FlatmapIterator(this, transform);
  }

  /**
   * Apply a function to every element of the stream.