return valueComparator.compare(
                  requireNonNull(map.get(left)), requireNonNull(map.get(right)));
            }
          };
      return keyOrdering.immutableSortedCopy(map.keySet());
    }

    abstract Class<?> getRawType(K type);

    abstract Iterable<? extends K> getInterfaces(K type);

    abstract @Nullable K getSuperclass(K type);