code: private static QualityValue evaluateAcceptParameters(Map<String, String> parameters)
     {
        Iterator<String> i = parameters.keySet().iterator();
        while (i.hasNext())
        {
           String name = i.next();
           if ("q".equals(name))
           {
              if (i.hasNext())
              {
                 logger.debug("Accept extensions not supported.");
                 i.remove();
                 do
                 {
                    i.next();
                    i.remove();
                 } while (i.hasNext());
                 return QualityValue.NOT_ACCEPTABLE;
              }
              else
              {
                 String value = parameters.get(name);
                 i.remove();
                 return QualityValue.valueOf(value);
              }
           }
        }
        return QualityValue.DEFAULT;
     }
docs: Evaluates and removes the accept parameters.
  <pre>
  accept-params  = ";" "q" "=" qvalue *( accept-extension )
  accept-extension = ";" token [ "=" ( token | quoted-string ) ]
  </pre>
  
  @param parameters all parameters in order of appearance.
  @return the qvalue.
  @see "accept-params