backward.put(value, key);
  }

  /**
   * Returns an immutable set of all nine primitive types (including {@code void}). Note that a
   * simpler way to test whether a {@code Class} instance is a member of this set is to call {@link
   * Class#isPrimitive}.
   *
   * @since 3.0
   */
  public static Set<Class<?>> allPrimitiveTypes() {
    return PRIMITIVE_TO_WRAPPER_TYPE.keySet();
  }

  /**

        return true;
      }
    }
    return false;
  }

  private boolean isIgnored(Member member) {
    return member.isSynthetic() || ignoredMembers.contains(member) || isEquals(member);
  }

  /**
   * Returns true if the given member is a method that overrides {@link Object#equals(Object)}.
   *

   *
   * <pre>{@code
   * List<Class<?>> classes = Arrays.asList(
   *     Object.class, String.class, Number.class, Long.class);
   * return Iterables.filter(classes, subtypeOf(Number.class));
   * }</pre>
   *
   * The code above returns an iterable containing {@code Number.class} and {@code Long.class}.
   *
   * @since 20.0 (since 10.0 under the incorrect name {@code assignableFrom})
   */

    if (componentType == null) {
      return null;
    }
    return of(componentType);
  }

  /**
   * Returns the {@link Invokable} for {@code method}, which must be a member of {@code T}.
   *
   * @since 14.0
   */
  public final Invokable<T, Object> method(Method method) {
    checkArgument(
        this.someRawTypeIsSubclassOf(method.getDeclaringClass()),

    // Serialization invokes writeObject only when it's private.
    // The SynchronizedObject subclasses don't need a writeObject method since
    // they don't contain any non-transient member variables, while the
    // following writeObject() handles the SynchronizedObject members.

    @GwtIncompatible // java.io.ObjectOutputStream
    @J2ktIncompatible
    private void writeObject(ObjectOutputStream stream) throws IOException {

  }

  /**
   * Returns the number of times the current thread has entered this monitor in excess of the number
   * of times it has left. Returns 0 if the current thread is not occupying this monitor.
   */
  public int getOccupiedDepth() {
    return lock.getHoldCount();
  }

  /**
   * Returns an estimate of the number of threads waiting to enter this monitor. The value is only

/*
 * Written by Doug Lea and Martin Buchholz with assistance from
 * members of JCP JSR-166 Expert Group and released to the public
 * domain, as explained at
 * http://creativecommons.org/publicdomain/zero/1.0/
 */

/*
 * Source:
 * http://gee.cs.oswego.edu/cgi-bin/viewcvs.cgi/jsr166/src/test/tck-jsr166e/AtomicDoubleArrayTest.java?revision=1.13
 * (Modified to adapt to guava coding conventions)
 */

package com.google.common.util.concurrent;

@ElementTypesAreNonnullByDefault
public interface Multimap<K extends @Nullable Object, V extends @Nullable Object> {
  // Query Operations

  /**
   * Returns the number of key-value pairs in this multimap.
   *
   * <p><b>Note:</b> this method does not return the number of <i>distinct keys</i> in the multimap,
   * which is given by {@code keySet().size()} or {@code asMap().size()}. See the opening section of

/*
 * Written by Doug Lea and Martin Buchholz with assistance from
 * members of JCP JSR-166 Expert Group and released to the public
 * domain, as explained at
 * http://creativecommons.org/publicdomain/zero/1.0/
 */

/*
 * Source:
 * http://gee.cs.oswego.edu/cgi-bin/viewcvs.cgi/jsr166/src/test/tck-jsr166e/AtomicDoubleArrayTest.java?revision=1.13
 * (Modified to adapt to guava coding conventions)
 */

package com.google.common.util.concurrent;

    Optional<Integer> optionalInt = getSomeOptionalInt();
    // Number value = optionalInt.or(0.5); // error
  }

  @SuppressWarnings("unused") // compilation test
  public void testSampleCodeError2() {
    FluentIterable<? extends Number> numbers = getSomeNumbers();
    Optional<? extends Number> first = numbers.first();
    // Number value = first.or(0.5); // error
  }

  @SuppressWarnings("unused") // compilation test