public void testSize0() {
    Iterable<String> iterable = Collections.emptySet();
    assertEquals(0, Iterables.size(iterable));
  }

  public void testSize1Collection() {
    Iterable<String> iterable = Collections.singleton("a");
    assertEquals(1, Iterables.size(iterable));
  }

  public void testSize2NonCollection() {
    Iterable<Integer> iterable =
        new Iterable<Integer>() {
          @Override

  public void testSize0() {
    Iterable<String> iterable = Collections.emptySet();
    assertEquals(0, Iterables.size(iterable));
  }

  public void testSize1Collection() {
    Iterable<String> iterable = Collections.singleton("a");
    assertEquals(1, Iterables.size(iterable));
  }

  public void testSize2NonCollection() {
    Iterable<Integer> iterable =
        new Iterable<Integer>() {
          @Override

    } catch (UnsupportedOperationException expected) {
    }
  }

  /**
   * Verifies that an Iterator is unmodifiable.
   *
   * <p>This test only works with iterators that iterate over a finite set.
   */
  public static void assertIteratorIsUnmodifiable(Iterator<?> iterator) {
    while (iterator.hasNext()) {
      iterator.next();
      try {
        iterator.remove();

     * @since 19.0
     */
    @CanIgnoreReturnValue
    @Override
    public Builder<K, V> putAll(Iterable<? extends Entry<? extends K, ? extends V>> entries) {
      super.putAll(entries);
      return this;
    }

    @CanIgnoreReturnValue
    @Override
    public Builder<K, V> putAll(K key, Iterable<? extends V> values) {
      super.putAll(key, values);
      return this;
    }

     *
     * @param elements the {@code Iterable} to add to the {@code ImmutableMultiset}
     * @return this {@code Builder} object
     * @throws NullPointerException if {@code elements} is null or contains a null element
     */
    @CanIgnoreReturnValue
    @Override
    public Builder<E> addAll(Iterable<? extends E> elements) {
      if (elements instanceof Multiset) {

      super(backingList);
    }
  }

  /** Used to avoid http://bugs.sun.com/view_bug.do?bug_id=6558557 */
  static <T extends @Nullable Object> List<T> cast(Iterable<T> iterable) {
    return (List<T>) iterable;
  }

      Comparator<? super E> comparator, Collection<? extends E> elements) {
    return copyOf(comparator, (Iterable<? extends E>) elements);
  }

  /**
   * Returns an immutable sorted set containing the elements of a sorted set, sorted by the same
   * {@code Comparator}. That behavior differs from {@link #copyOf(Iterable)}, which always uses the
   * natural ordering of the elements.
   *

     *
     * @param elements the {@code Iterable} to add to the {@code ImmutableSortedMultiset}
     * @return this {@code Builder} object
     * @throws NullPointerException if {@code elements} is null or contains a null element
     */
    @CanIgnoreReturnValue
    @Override
    public Builder<E> addAll(Iterable<? extends E> elements) {
      super.addAll(elements);
      return this;
    }

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.

    So, it is a generator function that transfers the "generating" work to something else internally.

 *       ordering is otherwise specified (e.g. {@link ImmutableSortedSet#naturalOrder}). See the
 *       appropriate factory method for details. View collections such as {@link
 *       ImmutableMultiset#elementSet} iterate in the same order as the parent, except as noted.
 *   <li><b>Thread safety.</b> It is safe to access this collection concurrently from multiple
 *       threads.