docs: @Nonnull
    public QValue getQValueOfCharset (@Nonnull final String sCharset)
    {
      ValueEnforcer.notNull (sCharset, "Charset");
  
      // Find charset direct
      QValue aQuality = m_aMap.get (_unify (sCharset));
      if (aQuality == null)
      {
        // If not explicitly given, check for "*"
        aQuality = m_aMap.get (AcceptCharsetHandler.ANY_CHARSET);
        if (aQuality == null)
        {
          // Neither charset nor "*" is present
          return sCharset.equals (AcceptCharsetHandler.DEFAULT_CHARSET) ? QValue.MAX_QVALUE : QValue.MIN_QVALUE;
        }
      }
      return aQuality;
    }