}

    void clear() {
      value = null;
    }
  }

  private static final class AvlNode<E extends @Nullable Object> {
    /*
     * For "normal" nodes, the type of this field is `E`, not `@Nullable E` (though note that E is a
     * type that can include null, as in a TreeMultiset<@Nullable String>).
     *
     * For the header node, though, this field contains `null`, regardless of the type of the
     * multiset.

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

/**
 * An immutable {@code Map.Entry}, used both by {@link
 * com.google.common.collect.Maps#immutableEntry(Object, Object)} and by other parts of {@code
 * common.collect} as a superclass.
 */
@GwtCompatible(serializable = true)
@ElementTypesAreNonnullByDefault
class ImmutableEntry<K extends @Nullable Object, V extends @Nullable Object>

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

/**
 * An iterator that transforms a backing iterator; for internal use. This avoids the object overhead
 * of constructing a {@link com.google.common.base.Function Function} for internal methods.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
abstract class TransformedIterator<F extends @Nullable Object, T extends @Nullable Object>

  }

  public void testNullFriendlyTransform() {
    Iterator<@Nullable Integer> input = Arrays.<@Nullable Integer>asList(1, 2, null, 3).iterator();
    Iterator<String> result =
        Iterators.transform(
            input,
            new Function<@Nullable Integer, String>() {
              @Override
              public String apply(@Nullable Integer from) {
                return String.valueOf(from);
              }

import java.util.concurrent.Callable;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * An abstract {@code ScheduledExecutorService} that allows subclasses to {@linkplain
 * #wrapTask(Callable) wrap} tasks before they are submitted to the underlying executor.
 *

import java.util.Iterator;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * An {@code Iterable} whose elements are sorted relative to a {@code Comparator}, typically
 * provided at creation time.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
interface SortedIterable<T extends @Nullable Object> extends Iterable<T> {
  /**

 * limitations under the License.
 */

package com.google.common.collect.testing;

import com.google.common.annotations.GwtCompatible;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * An unhashable object to be used in testing as values in our collections.
 *
 * @author Regina O'Dell
 */
@GwtCompatible
public class UnhashableObject implements Comparable<UnhashableObject> {

 * limitations under the License.
 */

package com.google.common.eventbus.outside;

import com.google.common.eventbus.EventBus;
import junit.framework.TestCase;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Abstract base class for tests that EventBus finds the correct subscribers.
 *
 * <p>The actual tests are distributed among the other classes in this package based on whether they

import java.util.Iterator;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * An {@code Iterable} whose elements are sorted relative to a {@code Comparator}, typically
 * provided at creation time.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
interface SortedIterable<T extends @Nullable Object> extends Iterable<T> {
  /**

  }

  @GwtIncompatible // not present in emulated superclass
  @Override
  int copyIntoArray(@Nullable Object[] dst, int offset) {
    return delegateList.copyIntoArray(dst, offset);
  }

  @Override
  @CheckForNull
  @Nullable
  Object[] internalArray() {
    return delegateList.internalArray();
  }

  @Override
  int internalArrayStart() {