assertEquals("Correct string should be delivered.", EVENT, events.get(0));
  }

  /**
   * Tests that events are distributed to any subscribers to their type or any supertype, including
   * interfaces and superclasses.
   *
   * <p>Also checks delivery ordering in such cases.
   */
  public void testPolymorphicDistribution() {
    // Three catchers for related types String, Object, and Comparable<?>.

    assertEquals("Correct string should be delivered.", EVENT, events.get(0));
  }

  /**
   * Tests that events are distributed to any subscribers to their type or any supertype, including
   * interfaces and superclasses.
   *
   * <p>Also checks delivery ordering in such cases.
   */
  public void testPolymorphicDistribution() {
    // Three catchers for related types String, Object, and Comparable<?>.

   *
   * <p>This method is declared to accept any 2 {@code Comparable} objects, even if they are not <a
   * href="https://docs.oracle.com/javase/tutorial/collections/interfaces/order.html">mutually
   * comparable</a>. If you pass objects that are not mutually comparable, this method may throw an
   * exception. (The reason for this decision is lost to time, but the reason <i>might</i> be that

   *
   * <p>Java 8 introduced a new method {@code getAnnotatedBounds()} in the {@link TypeVariable}
   * interface, whose return type {@code AnnotatedType[]} is also new in Java 8. That means that we
   * cannot implement that interface in source code in a way that will compile on both Java 7 and
   * Java 8. If we include the {@code getAnnotatedBounds()} method then its return type means it

import java.util.Set;
import javax.annotation.CheckForNull;

/**
 * An interface for <a
 * href="https://en.wikipedia.org/wiki/Graph_(discrete_mathematics)">graph</a>-structured data,
 * whose edges have associated non-unique values.
 *
 * <p>A graph is composed of a set of nodes and a set of edges connecting pairs of nodes.
 *
 * <p>There are three primary interfaces provided to represent graphs. In order of increasing

    private final Map<TypeVariableKey, Type> mappings = Maps.newHashMap();

    /**
     * Returns type mappings using type parameters and type arguments found in the generic
     * superclass and the super interfaces of {@code contextClass}.
     */
    static ImmutableMap<TypeVariableKey, Type> getTypeMappings(Type contextType) {
      checkNotNull(contextType);

 *       these guarantees to be violated).
 * </ul>
 *
 * <h4>"Interfaces", not implementations</h4>
 *
 * <p>These are classes instead of interfaces to prevent external subtyping, but should be thought
 * of as interfaces in every important sense. Each public class such as {@link ImmutableSet} is a

 *       these guarantees to be violated).
 * </ul>
 *
 * <h4>"Interfaces", not implementations</h4>
 *
 * <p>These are classes instead of interfaces to prevent external subtyping, but should be thought
 * of as interfaces in every important sense. Each public class such as {@link ImmutableSet} is a

 *
 * <p>Events are routed based on their type &mdash; an event will be delivered to any subscriber for
 * any type to which the event is assignable. This includes implemented interfaces, all
 * superclasses, and all interfaces implemented by superclasses.
 *
 * <p>When {@code post} is called, all registered subscribers for an event are run in sequence, so

              @Override
              public Sub apply(Sub sub) {
                return new ForwardingSub(sub);
              }
            });
  }

  interface Base {
    CharSequence getId();
  }

  interface Sub extends Base {
    @Override
    String getId();
  }

  private static class ForwardingSub implements Sub {
    private final Sub delegate;