code: List<SortProperty> convert2SortProperty(final List<SortMeta> sortMetas) {
  		List<SortProperty> sortProperties = new ArrayList<SortProperty>(
  				sortMetas.size());
  		for (SortMeta sortMeta : sortMetas) {
  			final SortOrder order = sortMeta.getSortOrder();
  			if (order == SortOrder.ASCENDING || order == SortOrder.DESCENDING) {
  				sortProperties.add(new SortProperty(sortMeta.getSortField(),
  						convert2SortPropertyOrder(order)));
  			}
  		}
  		return sortProperties;
  	}
docs: Converts a list of PrimeFaces SortMeta to a list of DC SortPropertyOrder
  
  @param sortMetas
  @return converted list
  @throws IllegalArgumentException
  if no conversion possible