docs: @Nonnull
    public HCConversionSettings setHTMLVersion (@Nonnull final EHTMLVersion eHTMLVersion)
    {
      ValueEnforcer.notNull (eHTMLVersion, "HTMLVersion");
      m_eHTMLVersion = eHTMLVersion;
      m_sHTMLNamespaceURI = eHTMLVersion.getNamespaceURI ();
      return this;
    }