code: @Override
  	public List<V> load(final int first, final int pageSize,
  			final List<SortMeta> multiSortMeta,
  			final Map<String, Object> filters) {
  
  		final boolean filtersChanged = handleFilters(filters);
  		final boolean sortOrderChanged = handleSortOrder(multiSortMeta);
  		boolean notify = false;
  
  		// clear cache
  		if (filtersChanged || sortOrderChanged) {
  			adaptee.clearCache();
  			notify = filtersChanged || notifyOnSortOrderChanges;
  		}
  
  		adaptee.setPageSize(pageSize);
  		final int size = adaptee.getSize();
  		adaptee.setFirst(first >= size ? Math.max(0, size - 1) : first);
  		setRowCount(size);
  
  		// notify observers
  		if (filtersChanged && clearSelectionOnFilterChanges) {
  			adaptee.clearSelection();
  		}
  		if (notify) {
  			adaptee.notify(ChangeEventType.DATA);
  		}
  
  		return adaptee.getData();
  	}
docs: PF load for multiple sort support