* <p>Null nodes are strictly forbidden.
 *
 * <p>Because this is an abstract class, not an interface, you can't use a lambda expression to
 * implement it:
 *
 * {@snippet :
 * // won't work
 * TreeTraverser<NodeType> traverser = node -> node.getChildNodes();
 * }
 *
 * Instead, you can pass a lambda expression to the {@code using} factory method:
 *
 * {@snippet :

     * @param regex The regular expression for the client.
     * @param client The CrawlerClient instance.
     */
    @Override
    public void addClient(final String regex, final CrawlerClient client) {
        factory.addClient(regex, client);
    }

    /**
     * Adds a client to the wrapped factory at a specific position.
     * @param regex The regular expression for the client.

import org.codehaus.plexus.interpolation.PrefixedValueSourceWrapper;
import org.codehaus.plexus.interpolation.RecursionInterceptor;
import org.codehaus.plexus.interpolation.ValueSource;

/**
 * Use a regular expression search to find and resolve expressions within the POM.
 *
 * @deprecated use {@code org.apache.maven.api.services.ModelBuilder} instead
 */
@Deprecated(since = "4.0.0")

Create functions with a name that starts with `test_` (this is standard `pytest` conventions).

Use the `TestClient` object the same way as you do with `httpx`.

Write simple `assert` statements with the standard Python expressions that you need to check (again, standard `pytest`).

{* ../../docs_src/app_testing/tutorial001_py310.py hl[2,12,15:18] *}

/// tip

Notice that the testing functions are normal `def`, not `async def`.

 *
 * <p>Note on class-level isolation: Compiled Script classes are cached and reused.
 * Class-level state (static fields, metaclass mutations) persists across evaluations
 * of the same script. In Fess, scripts are short expressions configured by
 * administrators (e.g., "data1 &gt; 10", "10 * boost1 + boost2") and do not use
 * static state, so this is acceptable.</p>
 *
 * <p>Resource Management: Each cached entry's GroovyClassLoader is closed on

 *   }
 * };
 * LoadingCache<Key, Graph> cache = CacheBuilder.newBuilder().build(loader);
 * }
 *
 * <p>Since this example doesn't support reloading or bulk loading, if you're able to use lambda
 * expressions it can be specified even more easily:
 *
 * {@snippet :
 * CacheLoader<Key, Graph> loader = CacheLoader.from(key -> createExpensiveGraph(key));
 * }
 *
 * @author Charles Fry
 * @since 10.0
 */

 *       create a "fake" converter for a unit test. It is unnecessary (and confusing) to <i>mock</i>
 *       the {@code Converter} type using a mocking framework.
 *   <li>Pass two lambda expressions or method references to the {@link #from from} factory method.
 *   <li>Extend this class and implement its {@link #doForward} and {@link #doBackward} methods.
 * </ul>
 *
 * <p>Using a converter:
 *
 * <ul>

        Object result = scriptEngine.evaluate(template, paramMap);
        assertEquals("Price: $100 (with 20% off)", result);
    }

    // Test evaluate method with nested expressions
    @Test
    public void test_evaluate_withNestedExpressions() {
        String template = "${level1.level2.value}";
        Map<String, Object> paramMap = new HashMap<>();

 *       create a "fake" converter for a unit test. It is unnecessary (and confusing) to <i>mock</i>
 *       the {@code Converter} type using a mocking framework.
 *   <li>Pass two lambda expressions or method references to the {@link #from from} factory method.
 *   <li>Extend this class and implement its {@link #doForward} and {@link #doBackward} methods.
 * </ul>
 *
 * <p>Using a converter:
 *
 * <ul>

        BuildContainer(Element element, String sectionName) {
            this.element = element;
            this.sectionName = sectionName;
        }
    }

    /**
     * Fixes unsupported repository URL expressions.
     */
    private boolean fixUnsupportedRepositoryExpressions(Document pomDocument, UpgradeContext context) {
        Element root = pomDocument.root();

        // Collect all repository containers to process