atk4\data\tests\ExpressionSQLTest::testNakedExpression PHP Method

    public function testNakedExpression()
    {
        $db = new Persistence_SQL($this->db->connection);
        $m = new Model($db, false);
        $m->addExpression('x', '2+3');
        $m->tryLoadAny();
        $this->assertEquals(5, $m['x']);
    }