function urlChunkIterator(_x, _x2) {
	  return _urlChunkIterator.apply(this, arguments);
	} // Generate RequestInit from Request to match tf.util.fetch signature.
Provide a stream of chunks from a URL.

Note this class first downloads the entire file into memory before providing
the first element from the stream.  This is because the Fetch API does not
yet reliably provide a reader stream for the response body.