public function turnSelectColumnsToAliases(Criteria $criteria)
    {
        $selectColumns = $criteria->getSelectColumns();
        // clearSelectColumns also clears the aliases, so get them too
        $asColumns = $criteria->getAsColumns();
        $criteria->clearSelectColumns();
        $columnAliases = $asColumns;
        // add the select columns back
        foreach ($selectColumns as $clause) {
            // Generate a unique alias
            $baseAlias = preg_replace('/\W/', '_', $clause);
            $alias = $baseAlias;
            // If it already exists, add a unique suffix
            $i = 0;
            while (isset($columnAliases[$alias])) {
                $i++;
                $alias = $baseAlias . '_' . $i;
            }
            // Add it as an alias
            $criteria->addAsColumn($alias, $clause);
            $columnAliases[$alias] = $clause;
        }
        // Add the aliases back, don't modify them
        foreach ($asColumns as $name => $clause) {
            $criteria->addAsColumn($name, $clause);
        }

        return $criteria;
    }