public function testAggregateMax()
 {
     // Get user with the max of `id`
     $user_max = Model\User::max();
     // Consist
     $this->assertInstanceOf('Gas\\ORM', $user_max);
     $this->assertInstanceOf('Gas\\Data', $user_max->record);
     // The max id would be '4'
     $this->assertEquals($user_max->id, '4');
 }