public function getClauses()
    {
        // This is a cheap fix for `SELECT` statements that contain `UNION`.
        // The `ORDER BY` and `LIMIT` clauses should be at the end of the
        // statement.
        if (! empty($this->union)) {
            $clauses = static::$CLAUSES;
            unset($clauses['ORDER BY'], $clauses['LIMIT']);
            $clauses['ORDER BY'] = [
                'ORDER BY',
                3,
            ];
            $clauses['LIMIT'] = [
                'LIMIT',
                3,
            ];

            return $clauses;
        }

        return static::$CLAUSES;
    }