checkCanReserializeSingleton(Functions.toStringFunction());
  }

  @J2ktIncompatible
  @GwtIncompatible // NullPointerTester
  public void testNullPointerExceptions() {
    NullPointerTester tester = new NullPointerTester();
    tester.testAllPublicStaticMethods(Functions.class);
  }

  public void testForMapWithoutDefault() {
    Map<String, @Nullable Integer> map = new HashMap<>();
    map.put("One", 1);
    map.put("Three", 3);

        .createTestSuite();
  }

  @J2ktIncompatible
  @GwtIncompatible // NullPointerTester
  public void testNullPointerExceptions() {
    NullPointerTester tester = new NullPointerTester();
    tester.testAllPublicStaticMethods(Collections2.class);
  }

  public void testOrderedPermutationSetEmpty() {
    List<Integer> list = new ArrayList<>();

import java.util.List;
import java.util.Objects;
import java.util.function.BiPredicate;
import java.util.stream.Collector;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * Tester for {@code Collector} implementations.
 *
 * <p>Example usage:
 *
 * <pre>
 * CollectorTester.of(Collectors.summingInt(Integer::parseInt))
 *     .expectCollects(3, "1", "2")

import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.testing.features.CollectionSize;
import com.google.common.collect.testing.features.MapFeature;
import org.junit.Ignore;

/** Tester for {@code BiMap.put} and {@code BiMap.forcePut}. */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")

import com.google.common.collect.testing.features.CollectionSize;
import com.google.common.collect.testing.features.MapFeature;
import java.util.Iterator;
import java.util.Map.Entry;
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")

        list.addLast("2");
        list.addLast("3");
        assertThat(SerializeUtil.serialize(list), is(notNullValue()));
    }

    /**
     * @throws Exception
     */
    @Test
    public void testSet() throws Exception {
        list.addLast("1");
        list.addLast("2");
        list.addLast("3");
        list.set(1, "4");
        assertThat(list.get(1), is("4"));
    }

    /**

testing/internal-performance-testing/       @gradle/bt-developer-productivity
testing/internal-testing/                   @gradle/bt-developer-productivity
testing/precondition-tester                 @gradle/bt-developer-productivity

# Release coordination
packaging/core-platform/                        @gradle/bt-product-operations
packaging/distributions-dependencies/           @gradle/bt-product-operations

import java.util.Iterator;
import java.util.List;
import java.util.Map.Entry;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;
import org.junit.Ignore;

/**
 * Tester for {@link Multimap#put}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")

        assertThat(WildcardType.class.isInstance(GenericsUtil.getElementTypeOfList(t3)), is(true));
    }

    /**
     * @throws Exception
     */
    public void testSet() throws Exception {
        final Method m1 = SetType.class.getMethod("setOfString");
        final Type t1 = m1.getGenericReturnType();
        assertThat(GenericsUtil.isTypeOf(t1, Set.class), is(true));

import java.util.function.Consumer;
import java.util.function.Function;
import java.util.function.Supplier;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * Tester for {@code Spliterator} implementations.
 *
 * @since 21.0 (but only since 33.4.0 in the Android flavor)
 */
@GwtCompatible
@NullMarked
public final class SpliteratorTester<E extends @Nullable Object> {