API should have a convenience method for getting orderable concepts

public List<ConceptSearchResult> getOrderables(String phrase, Locale, boolean includeRetired, Integer start, Integer length){
    List<ConceptClass> MAPPED_CLASSES = null;
    //fetch the mapped concepts class into the list above from the order_type_class_map table
   
   //Call the dao method that does paging and takes several lists as parameters and pass in the list 
   //above to filter on the orderable concept classes.
   return dao.getConcepts(phrase, locales, includeRetired, MAPPED_CLASSES, excludeClasses, requireDatatypes,
		    excludeDatatypes, answersToConcept, start, size);
}