identifiers.put(ident, method);
          }
        }
      }
    }
    return ImmutableList.copyOf(identifiers.values());
  }

  /** Global cache of classes to their flattened hierarchy of supertypes. */
  private static final LoadingCache<Class<?>, ImmutableSet<Class<?>>> flattenHierarchyCache =
      CacheBuilder.newBuilder()
          .weakKeys()
          .build(

 * map from keys to <i>nonempty</i> collections of values:
 *
 * <ul>
 *   <li>a → 1, 2
 *   <li>b → 3
 * </ul>
 *
 * ... or as a single "flattened" collection of key-value pairs:
 *
 * <ul>
 *   <li>a → 1
 *   <li>a → 2
 *   <li>b → 3
 * </ul>
 *
 * <p><b>Important:</b> although the first interpretation resembles how most multimaps are

of anger, and tried to beat them off, and found herself lying on
the bank, with her head in the lap of her sister, who was gently
brushing away some dead leaves that had fluttered down from the
trees upon her face.

  `Wake up, Alice dear!' said her sister; `Why, what a long
sleep you've had!'

  `Oh, I've had such a curious dream!' said Alice, and she told

of anger, and tried to beat them off, and found herself lying on
the bank, with her head in the lap of her sister, who was gently
brushing away some dead leaves that had fluttered down from the
trees upon her face.

  `Wake up, Alice dear!' said her sister; `Why, what a long
sleep you've had!'

  `Oh, I've had such a curious dream!' said Alice, and she told