docs: @Nonnull
    public CSP2SourceList addHash (@Nonnull final EMessageDigestAlgorithm eMDAlgo,
                                   @Nonnull @Nonempty final byte [] aHashValue)
    {
      ValueEnforcer.notEmpty (aHashValue, "HashValue");
      return addHash (eMDAlgo, Base64.safeEncodeBytes (aHashValue));
    }