contains contributions from many people at Google, as well as:

Aakar Dwivedi, Akhil Goel, Alexander Grund, Alexander Pivovarov, Andrew Goodbody, Andrey Portnoy, Aneta Kaczyńska, AnetaKaczynska, ArkadebMisra, Ashiq Imran, Ayan Moitra, Ben Barsdell, Ben Creech, Benedikt Lorch, Bhavani Subramanian, Bianca Van Schaik, Chao, Chase Riley Roberts, Connor Flanagan, David Hall, David Svantesson, David Svantesson-Yeung, dependabot[bot], Dr. Christoph Mittendorf, Dragan Mladjenovic, ekuznetsov139, Eli...

 *
 * <p>{@link #setDefault} allows subclasses to specify default values for types.
 *
 * <p>This class incurs IO because it scans the classpath and reads classpath resources.
 *
 * @author Ben Yu
 * @since 14.0
 */
// TODO: Switch to JUnit 4 and use @Parameterized and @BeforeClass
// Note: @Test annotations are deliberate, as some subclasses specify @RunWith(JUnit4).
@GwtIncompatible
@J2ktIncompatible

import java.util.Map.Entry;
import java.util.Objects;
import java.util.concurrent.atomic.AtomicReference;
import org.jspecify.annotations.Nullable;

/**
 * Utilities for working with {@link Type}.
 *
 * @author Ben Yu
 */
final class Types {

  /** Class#toString without the "class " and "interface " prefixes */
  private static final Joiner COMMA_JOINER = Joiner.on(", ").useForNull("null");

 * target a lower API level. In the meantime, if you have support for method references you can use
 * an equivalence as a bi-predicate like this: {@code myEquivalence::equivalent}.
 *
 * @author Bob Lee
 * @author Ben Yu
 * @author Gregory Kick
 * @since 10.0 (<a href="https://github.com/google/guava/wiki/Compatibility">mostly
 *     source-compatible</a> since 4.0)
 */
@GwtCompatible
/*

 * class.
 *
 * @param <T> the type that owns this method or constructor.
 * @param <R> the return type of (or supertype thereof) the method or the declaring type of the
 *     constructor.
 * @author Ben Yu
 * @since 14.0 (no longer implements {@link AccessibleObject} or {@code GenericDeclaration} since
 *     31.0)
 */
public abstract class Invokable<T, R> implements AnnotatedElement, Member {

import java.util.Collections;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;
import org.jspecify.annotations.Nullable;

/**
 * Unit tests for {@link Invokable}.
 *
 * @author Ben Yu
 */
@AndroidIncompatible // lots of failures, possibly some related to bad equals() implementations?
@NullUnmarked
public class InvokableTest extends TestCase {

 * used when the type mapping isn't implied by the static type hierarchy, but provided through other
 * means such as an annotation or external configuration file.
 *
 * @author Ben Yu
 * @since 15.0
 */
public final class TypeResolver {

  private final TypeTable typeTable;

  public TypeResolver() {
    this.typeTable = new TypeTable();
  }

 * number types; reasonable default instance for other stateless types. For mutable types, a fresh
 * instance is created each time {@code get()} is called.
 *
 * @author Kevin Bourrillion
 * @author Ben Yu
 * @since 12.0
 */
@GwtIncompatible
@J2ktIncompatible
@NullMarked
public final class ArbitraryInstances {

  private static final Ordering<Field> BY_FIELD_NAME =
      new Ordering<Field>() {

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

/**
 * Unit test for {@link ArbitraryInstances}.
 *
 * @author Ben Yu
 */
@NullUnmarked
public class ArbitraryInstancesTest extends TestCase {

  public void testGet_primitives() {
    assertThat(ArbitraryInstances.get(void.class)).isNull();

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

/**
 * Unit test for {@link ArbitraryInstances}.
 *
 * @author Ben Yu
 */
@NullUnmarked
public class ArbitraryInstancesTest extends TestCase {

  public void testGet_primitives() {
    assertThat(ArbitraryInstances.get(void.class)).isNull();