public function testSetAggregationTypeObjectWithValidFieldId()
{
$pivot = new PivotDescription($this->dataTable);
$pivot->setDataFields(array('income', 'expense'));
$type = new AggregationType(AggregationType::AVG);
$pivot->setAggregationType('income', $type);
$actual = $pivot->getAggregationType('income');
$this->assertEquals($type, $actual, "Expect AVG type is set");
}
