/**
   * Not supported. Use {@link #naturalOrder}, which offers better type-safety, instead. This method
   * exists only to hide {@link ImmutableMap#builder} from consumers of {@code ImmutableSortedMap}.
   *
   * @throws UnsupportedOperationException always
   * @deprecated Use {@link ImmutableSortedMap#naturalOrder}, which offers better type-safety.
   */
  @DoNotCall("Use naturalOrder")
  @Deprecated

  /**
   * Not supported. Use {@link #naturalOrder}, which offers better type-safety, instead. This method
   * exists only to hide {@link ImmutableMap#builder} from consumers of {@code ImmutableSortedMap}.
   *
   * @throws UnsupportedOperationException always
   * @deprecated Use {@link ImmutableSortedMap#naturalOrder}, which offers better type-safety.
   */
  @DoNotCall("Use naturalOrder")
  @Deprecated

   * reference; instead use the reference this method <i>returns</i>. At runtime, these point to the
   * same instance, but only the returned reference has the correct generic type information to
   * ensure type safety. For best results, use the standard method-chaining idiom illustrated in the
   * class documentation above, configuring a builder and building your cache in a single statement.