boilerplate notice, with the fields enclosed by brackets "[]"
      replaced with your own identifying information. (Don't include
      the brackets!)  The text should be enclosed in the appropriate
      comment syntax for the file format. We also recommend that a
      file or class name and description of purpose be included on the
      same "printed page" as the copyright notice for easier

       */
      KeyList<K, V> keyList = requireNonNull(keyToKeyList.remove(node.key));
      keyList.count = 0;
      modCount++;
    } else {
      // requireNonNull is safe (under the conditions listed in the comment in the branch above).
      KeyList<K, V> keyList = requireNonNull(keyToKeyList.get(node.key));
      keyList.count--;

      if (node.previousSibling == null) {

      if (supportsRemove) {
        int initialSize = map.size();
        map.get(keyToRemove);
        map.remove(keyToRemove);
        // This line doesn't hold - see the Javadoc comments above.
        // assertEquals(expectedValue, oldValue);
        assertFalse(map.containsKey(keyToRemove));
        assertEquals(initialSize - 1, map.size());
      } else {

    for (int i = 0; i < elementCount; i++) {
      E element = (E) stream.readObject();
      add(element);
    }
  }

  /*
   * For discussion of the safety of the following methods, see the comments near the end of
   * CompactHashMap.
   */

  private Object requireTable() {
    return requireNonNull(table);
  }

  private int[] requireEntries() {
    return requireNonNull(entries);
  }

      if (supportsRemove) {
        int initialSize = map.size();
        map.get(keyToRemove);
        map.remove(keyToRemove);
        // This line doesn't hold - see the Javadoc comments above.
        // assertEquals(expectedValue, oldValue);
        assertFalse(map.containsKey(keyToRemove));
        assertEquals(initialSize - 1, map.size());
      } else {

* And the file `app/internal/admin.py` is another submodule: `app.internal.admin`.

<img src="/img/tutorial/bigger-applications/package.svg">

The same file structure with comments:

```
.
├── app                  # "app" is a Python package
│   ├── __init__.py      # this file makes "app" a "Python package"
│   ├── main.py          # "main" module, e.g. import app.main

   */
  /*
   * In certain circumstances, this field might theoretically not be visible to an afterDone() call
   * triggered by cancel(). For details, see the comments on the fields of TimeoutFuture.
   */
  @CheckForNull @LazyInit
  private ImmutableCollection<? extends ListenableFuture<? extends InputT>> futures;

  private final boolean allMustSucceed;

      boilerplate notice, with the fields enclosed by brackets "[]"
      replaced with your own identifying information. (Don't include
      the brackets!)  The text should be enclosed in the appropriate
      comment syntax for the file format. We also recommend that a
      file or class name and description of purpose be included on the
      same "printed page" as the copyright notice for easier

    long unused1;
    long unused2;
    long unused3;

    PaddedLock() {
      super(false);
    }
  }

  private static class PaddedSemaphore extends Semaphore {
    // See PaddedReentrantLock comment
    long unused1;
    long unused2;
    long unused3;

    PaddedSemaphore(int permits) {
      super(permits, false);
    }
  }

 *       class or its <i>trusted</i> dependencies is badly broken), this is what ordinary Java
 *       assertions are for. Note that assertions are not enabled by default; they are essentially
 *       considered "compiled comments."
 *   <li>An explicit {@code if/throw} (as illustrated below) is always acceptable; we still
 *       recommend using our {@link VerifyException} exception type. Throwing a plain {@link
 *       RuntimeException} is frowned upon.