code: protected FlushStrategy elementAsFlushStrategy(XMLStreamReader reader, Map<String, String> expressions)
        throws XMLStreamException, ParserException
     {
        String elementtext = rawElementText(reader);
  
        if (expressions != null && elementtext != null && elementtext.indexOf("${") != -1)
           expressions.put(CommonXML.ELEMENT_FLUSH_STRATEGY, elementtext);
        
        FlushStrategy result = FlushStrategy.forName(getSubstitutionValue(elementtext));
  
        if (result != FlushStrategy.UNKNOWN)
           return result;
  
        throw new ParserException(bundle.notValidFlushStrategy(elementtext));
     }
docs: convert an xml element in FlushStrategy value
  
  @param reader the StAX reader
  @param expressions expressions
  @return the flush strategy represention
  @throws XMLStreamException StAX exception
  @throws ParserException in case it isn't a number