public <T> Iterable<? super CharSequence> wildCardsDoNotMatchByLowerBound(
        List<? super String> list) {
      return notSubtype(list);
    }

    // Can't test getSupertype() or getSubtype() because JDK reflection doesn't consider
    // Foo<?> and Foo<? extends Bar> equal for class Foo<T extends Bar>
    @TestSubtype(suppressGetSupertype = true, suppressGetSubtype = true)

        return ImmutableMap.builder()
            .putAll(Lists.transform(keys, k -> Maps.immutableEntry(k, "dummy value")))
            .buildOrThrow();
      }
    },
    FORCE_JDK {
      @Override
      public Map<Object, Object> create(List<?> keys) {
        ImmutableMap.Builder<Object, Object> builder = ImmutableMap.builder();
        for (Object k : keys) {
          builder.put(k, "dummy value");

 * <p>In light of the significant enhancements to {@code Comparator} in Java 8, the overwhelming
 * majority of usages of {@code Ordering} can be written using only built-in JDK APIs. This class is
 * intended to "fill the gap" and provide those features of {@code Ordering} not already provided by
 * the JDK.
 *
 * @since 21.0
 * @author Louis Wasserman
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public final class Comparators {

 * </ul>
 *
 * <h3>The rest</h3>
 *
 * This package also contains some classes with niche use cases (e.g., {@link Utf8} and {@link
 * Defaults}), as well as a number of classes that have been superseded by additions to the JDK.
 */
@CheckReturnValue
@ParametersAreNonnullByDefault
package com.google.common.base;

import com.google.errorprone.annotations.CheckReturnValue;

    checkHelperVersion(NO_ATOMIC_FIELD_UPDATER, "SynchronizedAtomicHelper");

    // Run the corresponding FuturesTest test method in a new classloader that disallows
    // certain core jdk classes.
    ClassLoader oldClassLoader = Thread.currentThread().getContextClassLoader();
    Thread.currentThread().setContextClassLoader(NO_ATOMIC_FIELD_UPDATER);
    try {
      runTestMethod(NO_ATOMIC_FIELD_UPDATER);

  @GwtIncompatible // NullPointerTester
  public void testNulls() throws NoSuchMethodException {
    NullPointerTester tester = new NullPointerTester();
    // Necessary until JDK15:
    // https://bugs.openjdk.org/browse/JDK-8202469
    tester.ignore(Equivalence.class.getMethod("wrap", Object.class));

    tester.testAllPublicStaticMethods(Equivalence.class);
    tester.testAllPublicInstanceMethods(Equivalence.equals());

      assertThat(cache.asMap().values()).contains(value2);
      assertEquals(ImmutableSet.of(immutableEntry(key2, value2)), cache.asMap().entrySet());
    }
  }

  // fails in Maven with 64-bit JDK: http://code.google.com/p/guava-libraries/issues/detail?id=1568

  private void assertCleanup(
      LoadingCache<Integer, String> cache,
      CountingRemovalListener<Integer, String> removalListener) {

import org.checkerframework.checker.nullness.qual.Nullable;

@GwtCompatible(emulated = true)
@ReflectionSupport(value = ReflectionSupport.Level.FULL)
@ElementTypesAreNonnullByDefault
// Some Android 5.0.x Samsung devices have bugs in JDK reflection APIs that cause
// getDeclaredField to throw a NoSuchFieldException when the field is definitely there.
// Since this class only needs CAS on one field, we can avoid this bug by extending AtomicReference

 *       {@code NullPointerTester} would need are not available) and in case of <a
 *       href="https://bugs.openjdk.java.net/browse/JDK-8202469">JDK-8202469</a>
 * </ul>
 *
 * <p>This annotation is a temporary hack. We will remove it after we're able to adopt the <a
 * href="https://jspecify.dev/">JSpecify</a> nullness annotations and <a

 *       {@code NullPointerTester} would need are not available) and in case of <a
 *       href="https://bugs.openjdk.java.net/browse/JDK-8202469">JDK-8202469</a>
 * </ul>
 *
 * <p>This annotation is a temporary hack. We will remove it after we're able to adopt the <a
 * href="https://jspecify.dev/">JSpecify</a> nullness annotations and <a