## Install dependencies { #install-dependencies }

Make sure you create a [virtual environment](../virtual-environments.md){.internal-link target=_blank}, activate it, and install `jinja2`:

<div class="termy">

```console
$ pip install jinja2

---> 100%
```

</div>

## Using `Jinja2Templates` { #using-jinja2templates }

* Import `Jinja2Templates`.

 */
@NullUnmarked
public class SynchronizedQueueTest extends TestCase {

  protected Queue<String> create() {
    TestQueue<String> inner = new TestQueue<>();
    Queue<String> outer = Synchronized.queue(inner, inner.mutex);
    outer.add("foo"); // necessary because we try to remove elements later on
    return outer;
  }

  private static final class TestQueue<E> implements Queue<E> {

import java.util.Map;
import java.util.Set;
import org.jspecify.annotations.NullUnmarked;
import org.jspecify.annotations.Nullable;

@NullUnmarked
public class SynchronizedTableTest extends AbstractTableTest<Character> {
  private static final class TestTable<R, C, V> implements Table<R, C, V>, Serializable {
    private final Table<R, C, V> delegate = HashBasedTable.create();

 * override {@code offer} as well, either providing your own implementation, or delegating to the
 * provided {@code standardOffer} method.
 *
 * <p><b>{@code default} method warning:</b> This class does <i>not</i> forward calls to {@code
 * default} methods. Instead, it inherits their default implementations. When those implementations
 * invoke methods, they invoke methods on the {@code ForwardingQueue}.
 *

import junit.framework.TestCase;
import junit.framework.TestSuite;
import org.jspecify.annotations.NullUnmarked;

/**
 * Tests for {@code CompactHashMap}.
 *
 * @author Louis Wasserman
 */
@NullUnmarked
public class CompactHashMapTest extends TestCase {
  @AndroidIncompatible // test-suite builders
  public static Test suite() {
    TestSuite suite = new TestSuite();
    suite.addTest(
        MapTestSuiteBuilder.using(

import com.google.common.escape.CharEscaper;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;

/**
 * Tests for the {@link XmlEscapers} class.
 *
 * @author Alex Matevossian
 * @author David Beaumont
 */
@GwtCompatible
@NullUnmarked
public class XmlEscapersTest extends TestCase {

  public void testXmlContentEscaper() throws Exception {

   */
  @SuppressWarnings("serial") // This class is never serialized.
  static final class Segment<K, V> extends ReentrantLock {

    /*
     * TODO(fry): Consider copying variables (like evictsBySize) from outer class into this class.
     * It will require more memory but will reduce indirection.
     */

    /*

{* ../../docs_src/app_testing/tutorial002_py39.py hl[27:31] *}

/// note

For more details, check Starlette's documentation for <a href="https://www.starlette.dev/testclient/#testing-websocket-sessions" class="external-link" target="_blank">testing WebSockets</a>.

import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Writer;

import org.codelibs.core.exception.IORuntimeException;

/**
 * Utility class for {@link Writer} operations.
 *
 * @author koichik
 */
public abstract class WriterUtil {

    /**
     * Do not instantiate.
     */
    protected WriterUtil() {
    }

    /**

import org.codelibs.fess.util.ComponentUtil;

/**
 * Fess-specific crawler configuration that extends OpenSearchCrawlerConfig.
 * This class provides configuration settings for the Fess crawler including
 * index names, shard counts, and replica counts for queue, data, and filter indices.
 */
public class FessCrawlerConfig extends OpenSearchCrawlerConfig {

    /**
     * Default constructor.
     */
    public FessCrawlerConfig() {