public function testAddSelect()
{
$qb = new QueryBuilder($this->qf);
$this->assertCount(0, $qb->getColumns());
$qb->addSelect('selectorName', 'propertyName', 'columnName');
$this->assertCount(1, $qb->getColumns());
$qb->addSelect('selectorName', 'propertyName', 'columnName');
$this->assertCount(2, $qb->getColumns());
}