* not possible to protect against this if the file system doesn't.
   */
  @SuppressWarnings("ThreadPriorityCheck") // TODO: b/175898629 - Consider onSpinWait.
  public void testDirectoryDeletion_directorySymlinkRace() throws IOException {
    int iterations = isAndroid() ? 100 : 5000;
    for (DirectoryDeleteMethod method : EnumSet.allOf(DirectoryDeleteMethod.class)) {

   open, and any responsibility can be carried by a contributor who demonstrates the required
   capacity and competence.

 * **Be considerate**: People use our work, and we depend on the work of others. Consider users and
   colleagues before taking action. For example, changes to code, infrastructure, policy, and
   documentation may negatively impact others.

  ASSERT_EQ(error::INVALID_ARGUMENT, s.code());
  ASSERT_EQ(
      "Provided null gradient_function for 'Neg'.\nIf the intent is to treat "
      "this op as non-differentiable consider using RegisterNotDifferentiable "
      "or NotDifferentiableGradientFunction.",
      s.message());
  ASSERT_EQ(nullptr, outputs[0]);
}

// TODO(b/164171226): Enable this test with tfrt after AddInputList is

*...

      }
    }

    // Test _all_ allowed characters (including surrogate values).
    for (char ch = 0x20; ch <= 0xFFFD; ch++) {
      // There are a small number of cases to consider, so just do it manually.
      if (ch == '&') {
        assertEscaping(xmlEscaper, "&amp;", ch);
      } else if (ch == '<') {
        assertEscaping(xmlEscaper, "&lt;", ch);
      } else if (ch == '>') {

The `TestClient` is based on <a href="https://www.python-httpx.org" class="external-link" target="_blank">HTTPX</a>, and luckily, we can use it directly to test the API.

## Example

For a simple example, let's consider a file structure similar to the one described in [Bigger Applications](../tutorial/bigger-applications.md){.internal-link target=_blank} and [Testing](../tutorial/testing.md){.internal-link target=_blank}:

```
.
├── app

 *
 * @author Jared Levy
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
class StandardRowSortedTable<R, C, V> extends StandardTable<R, C, V>
    implements RowSortedTable<R, C, V> {
  /*
   * TODO(jlevy): Consider adding headTable, tailTable, and subTable methods,
   * which return a Table view with rows keys in a given range. Create a
   * RowSortedTable subinterface with the revised methods?
   */

  StandardRowSortedTable(

  private int remaining() {
    requireNonNull(seq); // safe as long as we call this only after checkOpen
    return seq.length() - pos;
  }

  /*
   * To avoid the need to call requireNonNull so much, we could consider more clever approaches,
   * such as:
   *
   * - Make checkOpen return the non-null `seq`. Then callers can assign that to a local variable or

  private int remaining() {
    requireNonNull(seq); // safe as long as we call this only after checkOpen
    return seq.length() - pos;
  }

  /*
   * To avoid the need to call requireNonNull so much, we could consider more clever approaches,
   * such as:
   *
   * - Make checkOpen return the non-null `seq`. Then callers can assign that to a local variable or

 * ListenableFuture} directly.
 *
 * <p>For interoperability between {@code ListenableFuture} and <b>{@code CompletableFuture}</b>,
 * consider <a href="https://github.com/lukas-krecan/future-converter">Future Converter</a>.
 *
 * @author Sven Mawson
 * @since 10.0 (replacing {@code Futures.makeListenable}, which existed in 1.0)
 */
@J2ktIncompatible