*
   * @since 2.0
   */
  public static class Builder<K, V> extends ImmutableMap.Builder<K, V> {
    private transient @Nullable Object[] keys;
    private transient @Nullable Object[] values;
    private final Comparator<? super K> comparator;

    /**
     * Creates a new builder. The returned builder is equivalent to the builder generated by {@link

  public void testToStringImplWithNullKeys() throws Exception {
    Map<@Nullable String, String> hashmap = Maps.newHashMap();
    hashmap.put("foo", "bar");
    hashmap.put(null, "baz");

    assertEquals(hashmap.toString(), Maps.toStringImpl(hashmap));
  }

  public void testToStringImplWithNullValues() throws Exception {
    Map<String, @Nullable String> hashmap = Maps.newHashMap();
    hashmap.put("foo", "bar");

  public void testToStringImplWithNullKeys() throws Exception {
    Map<@Nullable String, String> hashmap = Maps.newHashMap();
    hashmap.put("foo", "bar");
    hashmap.put(null, "baz");

    assertEquals(hashmap.toString(), Maps.toStringImpl(hashmap));
  }

  public void testToStringImplWithNullValues() throws Exception {
    Map<String, @Nullable String> hashmap = Maps.newHashMap();
    hashmap.put("foo", "bar");

   */
  interface Trusted<V extends @Nullable Object> extends ListenableFuture<V> {}

  /**
   * A less abstract subclass of AbstractFuture. This can be used to optimize setFuture by ensuring
   * that {@link #get} calls exactly the implementation of {@link AbstractFuture#get}.
   */
  abstract static class TrustedFuture<V extends @Nullable Object> extends AbstractFuture<V>
      implements Trusted<V> {

import java.util.function.Consumer;
import java.util.function.Function;
import java.util.stream.Collector;
import java.util.stream.Collectors;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A {@link NavigableMap} whose contents will never change, with many other important properties
 * detailed at {@link ImmutableCollection}.
 *

   *
   * <p>If {@code maximumSize} is zero, elements will be evicted immediately after being loaded into
   * cache. This can be useful in testing, or to disable caching temporarily.
   *
   * <p>This feature cannot be used in conjunction with {@link #maximumWeight}.
   *
   * @param maximumSize the maximum size of the cache

import java.util.stream.Collector;
import java.util.stream.Stream;
import junit.framework.Test;
import junit.framework.TestCase;
import junit.framework.TestSuite;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Unit test for {@code Sets}.
 *
 * @author Kevin Bourrillion
 * @author Jared Levy
 */
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
public class SetsTest extends TestCase {

import com.google.common.annotations.GwtCompatible;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Static convenience methods that help a method or constructor check whether it was invoked
 * correctly (that is, whether its <i>preconditions</i> were met).
 *

   * @param typeArg the actual type to substitute
   */
  /*
   * TODO(cpovirk): Is there any way for us to support TypeParameter instances for type parameters
   * that have nullable bounds? Unfortunately, if we change the parameter to TypeParameter<? extends
   * @Nullable X>, then users might pass a TypeParameter<Y>, where Y is a subtype of X, while still
   * passing a TypeToken<X>. This would be invalid. Maybe we could accept a TypeParameter<@PolyNull

import com.google.common.annotations.GwtCompatible;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Static convenience methods that help a method or constructor check whether it was invoked
 * correctly (that is, whether its <i>preconditions</i> were met).
 *