code: @Nonnull
    public HCConversionSettings setHTMLVersion (@Nonnull final EHTMLVersion eHTMLVersion)
    {
      ValueEnforcer.notNull (eHTMLVersion, "HTMLVersion");
      m_eHTMLVersion = eHTMLVersion;
      m_sHTMLNamespaceURI = eHTMLVersion.getNamespaceURI ();
      return this;
    }
docs: Change the HTML version. Note: this does NOT change the
  {@link XMLWriterSettings}!
  
  @param eHTMLVersion
  The HTML version to use.
  @return this