1. This is the generator function. It's a "generator function" because it contains `yield` statements inside.
2. By using a `with` block, we make sure that the file-like object is closed after the generator function is done. So, after it finishes sending the response.
3. This `yield from` tells the function to iterate over that thing named `file_like`. And then, for each part iterated, yield that part as coming from this generator function (`iterfile`).

  }

  /**
   * Helper method to grow the character buffer as needed, this only happens once in a while so it's
   * ok if it's in a method call. If the index passed in is 0 then no copying will be done.
   */
  private static char[] growBuffer(char[] dest, int index, int size) {
    if (size < 0) { // overflow - should be OutOfMemoryError but GWT/j2cl don't support it

        TreeConnectResponse response = null;
        try (SmbSessionImpl sess = getSession(); SmbTransportImpl transport = sess.getTransport()) {
            synchronized (transport) {

                // this needs to be done before the reference to the remote hostname later
                transport.ensureConnected();

                if (waitForState(transport) == 2) {
                    // already connected
                    return null;

    /*
     * Wait not just until the Future's value is set (as in future.get()) but
     * also until ListeningScheduledExecutorService's wrapper task is done
     * executing listeners, as detected by yielding control to afterExecute.
     */
    completed.await();
    assertTrue(future.isDone());
    assertThat(future.get()).isEqualTo(42);

      "scheduledTasks=[task two, task one]",
    )

    taskFaker.advanceUntil(200.µs)
    assertThat(log).containsExactly(
      "scheduledTasks=[task two, task one]",
      "scheduledTasks=[task one]",
    )

    taskFaker.advanceUntil(300.µs)
    assertThat(log).containsExactly(
      "scheduledTasks=[task two, task one]",
      "scheduledTasks=[task one]",
      "scheduledTasks=[]",
    )

   * that would have been produced in that idle time). So, if rate == 1 permit per second, and
   * arrivals come exactly one second after the previous, then storedPermits is _never_ increased --
   * we would only increase it for arrivals _later_ than the expected one second.
   */

  /**
   * This implements the following function where coldInterval = coldFactor * stableInterval.
   *
   * <pre>

	const bucketMetadataRefresh = 15 * time.Minute

	sleeper := newDynamicSleeper(2, 150*time.Millisecond, false)

	t := time.NewTimer(bucketMetadataRefresh)
	defer t.Stop()
	for {
		select {
		case <-ctx.Done():
			return
		case <-t.C:
			buckets, err := sys.objAPI.ListBuckets(ctx, BucketOptions{NoMetadata: true})
			if err != nil {
				internalLogIf(ctx, err, logger.WarningKind)
				break
			}

			if _, err := mustReadFull(tr.r, blk[:]); err != nil {
				return nil, err
			}
			s = blk.toSparse()
			continue
		}
		return spd, nil // Done
	}
}

// readGNUSparseMap1x0 reads the sparse map as stored in GNU's PAX sparse format
// version 1.0. The format of the sparse map consists of a series of

		// user or a "virtual" user (parent of an STS account).
		//
		// If parent is a regular user => policy mapping is done on that parent itself.
		//
		// If parent is "virtual" => policy mapping is done on the virtual
		// parent and that virtual parent is an stsUser.
		//
		// To load the appropriate mapping, we check the parent user type.

            dstIndex += ((AndXServerMessageBlock) this.andx).writeAndXWireFormat(dst, dstIndex);
        } else {
            // the andx smb is not of type andx so lets just write it here and
            // were done.
            final int andxStart = dstIndex;
            this.andx.wordCount = this.andx.writeParameterWordsWireFormat(dst, dstIndex);
            dstIndex += this.andx.wordCount + 1;
            this.andx.wordCount /= 2;