Create a StreamIterator on stream.
Source
factory StreamIterator(Stream<T> stream)
    // TODO(lrn): use redirecting factory constructor when type
    // arguments are supported.
    => new _StreamIteratorImpl<T>(stream);
    Create a StreamIterator on stream.
factory StreamIterator(Stream<T> stream)
    // TODO(lrn): use redirecting factory constructor when type
    // arguments are supported.
    => new _StreamIteratorImpl<T>(stream);