...and have the code for the tests just like before.

## Testing: extended example { #testing-extended-example }

Now let's extend this example and add more details to see how to test different parts.

### Extended **FastAPI** app file { #extended-fastapi-app-file }

Let's continue with the same file structure as before:

```
.
├── app
│   ├── __init__.py
│   ├── main.py

@NullMarked
public class HashMultimapTest extends TestCase {

  @J2ktIncompatible
  @GwtIncompatible // suite
  @AndroidIncompatible // test-suite builders
  public static Test suite() {
    TestSuite suite = new TestSuite();
    suite.addTest(
        SetMultimapTestSuiteBuilder.using(
                new TestStringSetMultimapGenerator() {
                  @Override

import java.util.concurrent.atomic.AtomicReference;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;

/**
 * Supplemental tests for {@link Monitor}.
 *
 * <p>This test class contains various test cases that don't fit into the test case generation in
 * {@link GeneratedMonitorTest}.
 *
 * @author Justin T. Sampson
 */
@NullUnmarked
public class SupplementalMonitorTest extends TestCase {

@NullMarked
public class HashMultimapTest extends TestCase {

  @J2ktIncompatible
  @GwtIncompatible // suite
  @AndroidIncompatible // test-suite builders
  public static Test suite() {
    TestSuite suite = new TestSuite();
    suite.addTest(
        SetMultimapTestSuiteBuilder.using(
                new TestStringSetMultimapGenerator() {
                  @Override

import org.junit.Ignore;

/**
 * A generic JUnit test which tests {@link Collection#removeIf}. Can't be invoked directly; please
 * see {@link com.google.common.collect.testing.CollectionTestSuiteBuilder}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")
// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.

import java.util.concurrent.atomic.AtomicReference;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;

/**
 * Supplemental tests for {@link Monitor}.
 *
 * <p>This test class contains various test cases that don't fit into the test case generation in
 * {@link GeneratedMonitorTest}.
 *
 * @author Justin T. Sampson
 */
@NullUnmarked
public class SupplementalMonitorTest extends TestCase {

                    "performanceTestFlakinessReport"
                } else {
                    "performanceTestReport"
                }

            artifactRules = """
testing/$performanceProjectName/build/performance-test-results.zip
"""
            if (performanceTestProject.performanceTests.any { it.testProjects.isNotEmpty() }) {
                val dependencyBuildIds =
                    performanceTestProject.performanceTests

import java.util.Iterator;
import org.junit.Ignore;

/**
 * Tester for {@code Multimap.entries}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")
// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")

 *
 * @author Louis Wasserman
 * @param <K> The key type of the tested multimap.
 * @param <V> The value type of the tested multimap.
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")
// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")
@NullMarked

import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;

/**
 * Test case for {@link ListenableFutureTask}.
 *
 * @author Sven Mawson
 */
@NullUnmarked
public class ListenableFutureTaskTest extends TestCase {

  private ExecutorService exec;