code: public static RuntimeException propagate(final @NonNull Throwable throwable) {
      Throwables.throwIfUnchecked(throwable);
      throw new RuntimeException(throwable);
    }
docs: Propagates {@code throwable} as-is if it is an instance of {@link RuntimeException} or
  {@link Error}, otherwise wraps it in a {@code RuntimeException} and then
  propagates.
  
  @param throwable the throwable
  @return nothing
  @see Throwables#propagate(Throwable)
  @see Throwables#throwIfUnchecked(Throwable)