util.concurrent, like nearly all our packages, has two .gwt.xml files: one
    for prod and one for tests. However, unlike our other packages, as of this
    writing it has test supersource but no prod supersource.

    GWT happens to use the prod .gwt.xml, so it looks for no supersource for
    tests, either. This causes it to fail to find AtomicLongMapTest.

                skipConditionally()
            }
        }

        fun BuildSteps.adHocPerformanceTest(tests: List<String>) {
            gradleStep(
                listOf(
                    "clean",
                    "performance:${testProject}PerformanceAdHocTest",
                    tests.map { """--tests "$it"""" }.joinToString(" "),
                    """--warmups 2 --runs 2 --checks none""",

### Tests { #tests }

* Helfen Sie mir zu überprüfen, dass der PR **Tests** hat.

* Überprüfen Sie, dass diese Tests vor dem PR **fehlschlagen**. 🚨

* Überprüfen Sie dann, dass diese Tests nach dem PR **bestanden** werden. ✅

import java.util.List;
import java.util.NavigableSet;
import java.util.Set;
import java.util.SortedSet;
import junit.framework.TestSuite;

/**
 * Creates, based on your criteria, a JUnit test suite that exhaustively tests a NavigableSet
 * implementation.
 */
@GwtIncompatible
public final class NavigableSetTestSuiteBuilder<E> extends SortedSetTestSuiteBuilder<E> {

    assertThat(result).contains("Custom thread name");
    task.cancel(true);
    exitLatch.await();
  }

  @J2ktIncompatible
  @GwtIncompatible // used only in GwtIncompatible tests
  private void awaitUnchecked(CyclicBarrier barrier) {
    try {
      barrier.await();
    } catch (Exception e) {
      throw new RuntimeException(e);
    }
  }

import org.jspecify.annotations.Nullable;

/**
 * Tests representing the contract of {@link Map}. Concrete subclasses of this base class test
 * conformance of concrete {@link Map} subclasses to that contract.
 *
 * @param <K> the type of keys used by the maps under test
 * @param <V> the type of mapped values used the maps under test
 * @author George van den Driessche
 */

import org.junit.Ignore;

/**
 * A generic JUnit test which tests add operations on a set. Can't be invoked directly; please see
 * {@link com.google.common.collect.testing.SetTestSuiteBuilder}.
 *
 * @author Kevin Bourrillion
 */
@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.Map.Entry;
import java.util.Set;
import org.junit.Ignore;

/**
 * Tests for {@link SetMultimap#replaceValues}.
 *
 * @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")

    // any values in that range. To see why, consider the case where:
    // safeMin <= {hi,lo} <= safeMax
    // where {hi,lo} are characters forming a surrogate pair such that:
    // codePointOf(hi, lo) > safeMax
    // which would result in the surrogate pair being (wrongly) considered safe.
    // If we clip the safe range used during the per-character tests so it is

It also includes what has changed, how validations are now more correct and strict, possible caveats, etc.

You can read it to understand better what has changed.

## Tests { #tests }

Make sure you have [tests](../tutorial/testing.md) for your app and you run them on continuous integration (CI).

This way, you can do the upgrade and make sure everything is still working as expected.