public function testGetForecastAmountByPeriod()
 {
     $purchase_service = new \shina\controlmybudget\PurchaseService($this->data_provider, new Date('2014-08-15'));
     $purchase = new \shina\controlmybudget\Purchase\Purchase();
     $purchase->date = new DateTime('2014-08-10');
     $purchase->place = 'Zona Sul';
     $purchase->amount = 2.1;
     $purchase_service->save($purchase, $this->user);
     $purchase = new \shina\controlmybudget\Purchase\Purchase();
     $purchase->date = new DateTime('2014-08-15');
     $purchase->place = 'Natalandia';
     $purchase->amount = 300;
     $purchase_service->save($purchase, $this->user);
     $purchase = new \shina\controlmybudget\Purchase\Purchase();
     $purchase->date = new DateTime('2014-08-18');
     $purchase->place = 'Casa do carnaval';
     $purchase->amount = 54.7;
     $purchase_service->save($purchase, $this->user);
     $amount = $purchase_service->getForecastAmountByPeriod(new DateTime('2014-08-01'), new DateTime('2014-08-31'), $this->user);
     $this->assertEquals(54.7, $amount);
 }