import com.google.errorprone.annotations.OverridingMethodsMustInvokeSuper;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;
import org.junit.Ignore;

/**
 * Base class for testers of classes (including {@link Collection} and {@link java.util.Map Map})
 * that contain elements.
 *
 * @param <C> the type of the container

     * @param language the language of the sources to return, or {@code null} for all languages
     */
    @Nonnull
    Stream<SourceRoot> getEnabledSourceRoots(
            @Nonnull Project project, @Nullable ProjectScope scope, @Nullable Language language);

    /**
     * Adds the given source to the given project.
     * If a source already exists for the given scope, language and directory,

import java.util.List;
import java.util.Set;
import java.util.logging.Logger;
import junit.framework.Test;
import junit.framework.TestCase;
import junit.framework.TestSuite;
import org.jspecify.annotations.Nullable;

/**
 * Creates, based on your criteria, a JUnit test suite that exhaustively tests the object generated
 * by a G, selecting appropriate tests by matching them against specified features.
 *

 */
public class OptionalUtil {

    /**
     * Default constructor.
     */
    private OptionalUtil() {
        // Default constructor
    }

    /**
     * Creates an OptionalEntity from a nullable entity.
     *
     * @param <T> the type of the entity
     * @param entity the entity (can be null)
     * @return the OptionalEntity
     */
    public static <T> OptionalEntity<T> ofNullable(final T entity) {

  public void testPutAllNullForbidden() {
    assertThrows(NullPointerException.class, () -> multimap().putAll(null, singletonList(v3())));
  }

  @SuppressWarnings("EmptyList") // ImmutableList doesn't support nullable element types
  @MapFeature.Require(SUPPORTS_PUT)
  public void testPutAllEmptyCollectionOnAbsentKey() {
    assertFalse(multimap().putAll(k3(), Collections.<V>emptyList()));
    expectUnchanged();
  }

 * <p>
 * Annotated fields must not be null after construction has completed.
 * <p>
 * When this annotation is applied to a method it applies to the method return value.
 *
 * @see Nullable
 * @since 4.0.0
 */
@Experimental
@Documented
@Retention(RetentionPolicy.CLASS)
@Target({ElementType.FIELD, ElementType.PARAMETER, ElementType.METHOD})

  }

  static <K extends @Nullable Object, V extends @Nullable Object>
      Map<K, V> newLinkedHashMapWithExpectedSize(int expectedSize) {
    return Maps.newLinkedHashMapWithExpectedSize(expectedSize);
  }

  static <E extends @Nullable Object> Set<E> newHashSetWithExpectedSize(int expectedSize) {
    return Sets.newHashSetWithExpectedSize(expectedSize);
  }

  static <E extends @Nullable Object> Set<E> newConcurrentHashSet() {

    runConcurrentTest(
        numberOfThreads,
        new Callable<@Nullable Void>() {
          @Override
          public @Nullable Void call() throws Exception {
            long unused = ticker.read();
            return null;
          }
        });

    assertEquals(incrementByNanos * numberOfThreads, ticker.read());
  }

  /** Runs {@code callable} concurrently {@code numberOfThreads} times. */

  }

  @Override
  public <T extends @Nullable Object> List<Future<T>> invokeAll(
      Collection<? extends Callable<T>> tasks) throws InterruptedException {
    return delegate().invokeAll(tasks);
  }

  @Override
  public <T extends @Nullable Object> List<Future<T>> invokeAll(
      Collection<? extends Callable<T>> tasks, long timeout, TimeUnit unit)
      throws InterruptedException {

    TreeMultimap<@Nullable String, @Nullable Integer> multimap = createPopulate();
    assertThat(multimap.entries())
        .containsExactly(
            Maps.<@Nullable String, Integer>immutableEntry(null, 7),
            Maps.<@Nullable String, Integer>immutableEntry(null, 3),
            Maps.<@Nullable String, Integer>immutableEntry(null, 1),
            Maps.<String, @Nullable Integer>immutableEntry("tree", null),