/**
  *
  * @dataProvider getGroupByStringProvider
  */
 public function testGetGroupByString($groupBys, $expected, $expectedFormatted)
 {
     foreach ($groupBys as $groupBy) {
         $this->queryBuilder->groupBy($groupBy[0], $groupBy[1]);
     }
     $this->assertEquals($expected, $this->queryBuilder->getGroupByString());
     $this->assertEquals($expectedFormatted, $this->queryBuilder->getGroupByString(true));
 }