import java.util.Collection;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A skeleton {@code Multimap} implementation, not necessarily in terms of a {@code Map}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.Collection;
import java.util.Map;
import java.util.Set;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Implementation of {@link Multimap} using hash tables.
 *
 * <p>The multimap does not store duplicate key-value pairs. Adding a new key-value pair equal to an

import java.util.Collection;
import java.util.Comparator;
import java.util.Iterator;
import java.util.NavigableSet;
import java.util.SortedSet;
import java.util.TreeSet;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A wrapper around {@code TreeSet} that aggressively checks to see if elements are mutually
 * comparable. This implementation passes the navigable set test suites.
 *
 * @author Louis Wasserman

import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.Collection;
import java.util.Iterator;
import java.util.Map.Entry;
import org.checkerframework.checker.nullness.qual.Nullable;
import org.junit.Ignore;

/**
 * Superclass for all {@code Multimap} testers.
 *
 * @author Louis Wasserman
 */
@GwtCompatible

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Map.Entry;
import java.util.NoSuchElementException;
import java.util.Set;
import org.checkerframework.checker.nullness.qual.Nullable;
import org.junit.Ignore;

/**
 * A generic JUnit test which tests {@code iterator} operations on a collection. Can't be invoked

import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import junit.framework.TestCase;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Tests for {@code Synchronized#map}.
 *
 * @author Mike Bostock
 */
public class SynchronizedMapTest extends TestCase {
  public final Object mutex = new Object[0]; // something Serializable

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.util.Arrays;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Abstract implementation of {@link InvocationHandler} that handles {@link Object#equals}, {@link
 * Object#hashCode} and {@link Object#toString}. For example:
 *
 * <pre>

import java.util.ArrayList;
import java.util.List;
import java.util.NoSuchElementException;
import java.util.Optional;
import java.util.stream.Collector;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Collectors not present in {@code java.util.stream.Collectors} that are not otherwise associated
 * with a {@code com.google.common} type.
 *
 * @author Louis Wasserman

import java.util.concurrent.CancellationException;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeoutException;
import junit.framework.AssertionFailedError;
import org.checkerframework.checker.nullness.qual.Nullable;

/** Replacements for JUnit's {@code assertThrows} that work under GWT/J2CL. */
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
final class ReflectionFreeAssertThrows {

import java.lang.reflect.Method;
import java.lang.reflect.Type;
import java.util.Arrays;
import java.util.Comparator;
import javax.lang.model.element.Modifier;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Tester of subtyping relationships between two types.
 *
 * <p>Tests should inherit from this class, and declare subtyping relationship with public methods
 * annotated by {@link TestSubtype}.