import jsinterop.annotations.JsType;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Java super source for ListenableFuture, implementing a structural thenable via a default method.
 * For restrictions, please refer to the documentation of the then() method.
 */
@ElementTypesAreNonnullByDefault
public interface ListenableFuture<V extends @Nullable Object> extends Future<V>, IThenable<V> {

   *
   * <p>This method should be overridden when bulk retrieval is significantly more efficient than
   * many individual lookups. Note that {@link LoadingCache#getAll} will defer to individual calls
   * to {@link LoadingCache#get} if this method is not overridden.
   *
   * @param keys the unique, non-null keys whose values should be loaded

import com.google.common.annotations.GwtCompatible;

/**
 * The subset of the {@link java.util.regex.Matcher} API which is used by this package, and also
 * shared with the {@code re2j} library. For internal use only. Please refer to the {@code Matcher}
 * javadoc for details.
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
abstract class CommonMatcher {
  public abstract boolean matches();

  public abstract boolean find();

 *
 * <p>For {@code ImmutableMultiset} in particular, I ran into a problem with the {@code
 * GwtSerializationDependencies} approach: When autogenerating a serializer for the new class, GWT
 * tries to refer to our dummy serializer for the superclass,
 * ImmutableMultiset_CustomFieldSerializer. But that type has no methods (since it's never actually
 * used). We could probably fix the problem by adding dummy methods to that class, but that is