protected function buildListExpression(ClassProfile $entity, $index = null, $group = null) {
		$expr = 'obj:' . $entity->getReflectionClass()->getName();
		
		if (isset($group))
			$expr .= '<' . $group . '>';	
		
		if (isset($index))
			$expr .= '[' . $index . ']';
		else
			$expr .= '[]';
		
		return $expr;
	}