}
  }

  /** Returns a serializable converter that always converts or reverses an object to itself. */
  @SuppressWarnings("unchecked") // implementation is "fully variant"
  public static <T> Converter<T, T> identity() {
    return (IdentityConverter<T>) IdentityConverter.INSTANCE;
  }

  /**

    }
  }

  /** Returns a serializable converter that always converts or reverses an object to itself. */
  @SuppressWarnings("unchecked") // implementation is "fully variant"
  public static <T> Converter<T, T> identity() {
    return (IdentityConverter<T>) IdentityConverter.INSTANCE;
  }

  /**