assertTrue(filtered.containsEntry("foo", 1));
    assertTrue(filtered.keySet().retainAll(asList("cat", "dog")));
    assertEquals(0, filtered.size());
  }

  // TODO(jlevy): Many more tests needed.

In the next test that same "live implementation" will be used in a stub version instead.

Not all live services have stubs, but can be added as needed.
</body>

  // TODO(user): Evaluate whether it makes sense to always piggyback the computation of a
  // HashCode on an existing OutputStream, compared to creating a separate OutputStream that could
  // be (optionally) be combined with another if needed (with something like
  // MultiplexingOutputStream).
  public HashingOutputStream(HashFunction hashFunction, OutputStream out) {
    super(checkNotNull(out));
    this.hasher = checkNotNull(hashFunction.newHasher());
  }

    assertTrue(filtered.containsEntry("foo", 1));
    assertTrue(filtered.keySet().retainAll(asList("cat", "dog")));
    assertEquals(0, filtered.size());
  }

  // TODO(jlevy): Many more tests needed.

   *
   * <p>The function is applied lazily, invoked when needed. This is necessary for the returned map
   * to be a view, but it means that the function will be applied many times for bulk operations
   * like {@link Map#containsValue} and {@code Map.toString()}. For this to perform well, {@code
   * function} should be fast. To avoid lazy evaluation when the returned map doesn't need to be a

   *
   * <p>The function is applied lazily, invoked when needed. This is necessary for the returned map
   * to be a view, but it means that the function will be applied many times for bulk operations
   * like {@link Map#containsValue} and {@code Map.toString()}. For this to perform well, {@code
   * function} should be fast. To avoid lazy evaluation when the returned map doesn't need to be a

And then, that system (in this case **FastAPI**) will take care of doing whatever is needed to provide your code with those needed dependencies ("inject" the dependencies).

This is very useful when you need to:

* Have shared logic (the same code logic again and again).
* Share database connections.
* Enforce security, authentication, role requirements, etc.

   * <p>The function is applied lazily, invoked when needed. This is necessary for the returned
   * multimap to be a view, but it means that the function will be applied many times for bulk
   * operations like {@link Multimap#containsValue} and {@code Multimap.toString()}. For this to
   * perform well, {@code function} should be fast. To avoid lazy evaluation when the returned

			t.Errorf("Testcase %d: newer release is available but got empty update message!", i+1)
		case output == "" && (testCase.dlURL == "" || testCase.older <= 0):
			// Valid no update message case. No further
			// validation needed.
			continue
		case !strings.Contains(output, line1):
			t.Errorf("Testcase %d: output '%s' did not contain line 1: '%s'", i+1, output, line1)
		case !strings.Contains(output, line2):

import junit.framework.TestCase;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * This abstract base class for testers allows the framework to inject needed information after
 * JUnit constructs the instances.
 *
 * <p>This class is emulated in GWT.
 *
 * @param <G> the type of the test generator required by this tester. An instance of G should