assertEquals(6, NbtAddress.UNKNOWN_MAC_ADDRESS.length);
    }

    @Test
    void testConstantsAreImmutable() {
        // Ensure constants are properly defined as final
        // This test just verifies the constants exist and are accessible
        String anyHosts = NbtAddress.ANY_HOSTS_NAME;
        String masterBrowser = NbtAddress.MASTER_BROWSER_NAME;
        String smbServer = NbtAddress.SMBSERVER_NAME;

import java.util.Random;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;

/**
 * Tests for {@link Monitor}, either interruptible or uninterruptible.
 *
 * @author Justin T. Sampson
 */
@NullUnmarked
public abstract class MonitorTestCase extends TestCase {

  public class TestGuard extends Monitor.Guard {
    private volatile boolean satisfied;

        // Override purge to avoid client operations
        ThumbnailManager testManager = new ThumbnailManager() {
            @Override
            public long purge(long expiry) {
                // Just count files that would be deleted
                return 1L;
            }
        };
        testManager.baseDir = tempDir;

        long result = testManager.purge(1L);

 * should not fail a test when it does. (The behavior of a {@code TearDown} that throws an exception
 * varies; see its documentation for details.) Use it just like a {@code TearDown}, except override
 * {@link #sloppyTearDown()} instead.
 *
 * @author Luiz-Otavio Zorzella
 * @since 10.0
 */
@GwtCompatible
@NullMarked

Because all the **fields actually change** (the type now includes `None` and they now have a default value of `None`), we need to **re-declare** them.

But doing that, in some minutes or hours the attackers would have guessed the correct username and password, with the "help" of our application, just using the time taken to answer.

#### Fix it with `secrets.compare_digest()` { #fix-it-with-secrets-compare-digest }

When you declare a default value for non-path parameters (for now, we have only seen query parameters), then it is not required.

If you don't want to add a specific value but just make it optional, set the default as `None`.

But when you want to make a query parameter required, you can just not declare any default value:

{* ../../docs_src/query_params/tutorial005.py hl[6:7] *}

import com.google.errorprone.annotations.Immutable;

/**
 * Explicitly named subinterface of {@link Supplier} that can be marked {@literal @}{@link
 * Immutable}.
 */
// TODO(cpovirk): Should we just use ChecksumType directly instead of defining this type?
@Immutable

    Optional<String> z = Optional.of("z");

    Comparator<Optional<String>> comparator = emptiesFirst(comparing(String::length));
    testComparator(comparator, empty, z, abc);

    // Just demonstrate that no explicit type parameter is required
    Comparator<Optional<String>> unused = emptiesFirst(naturalOrder());
  }

  public void testEmptiesLast() {
    Optional<String> empty = Optional.empty();

http://localhost:8000/items/
```

the default of `q` will be: `["foo", "bar"]` and your response will be:

```JSON
{
  "q": [
    "foo",
    "bar"
  ]
}
```

#### Using just `list` { #using-just-list }

You can also use `list` directly instead of `list[str]`:

{* ../../docs_src/query_params_str_validations/tutorial013_an_py39.py hl[9] *}

/// note