public function index()
 {
     $this->paymentRepository->reasonFilter('balance');
     $balancePaidIn = $this->paymentRepository->getTotalAmount();
     $this->paymentRepository->resetFilters();
     $this->paymentRepository->sourceFilter('balance');
     $balancePaidOut = $this->paymentRepository->getTotalAmount();
     $balanceLiability = $balancePaidIn - $balancePaidOut;
     $this->paymentRepository->resetFilters();
     $this->paymentRepository->reasonFilter('storage-box');
     $storageBoxLiability = $this->paymentRepository->getTotalAmount();
     $this->paymentRepository->resetFilters();
     $this->paymentRepository->reasonFilter('door-key');
     $doorKeyLiability = $this->paymentRepository->getTotalAmount();
     $laserCutterInvestment = $this->paymentRepository->getPaymentsByReference('laser-cutter')->sum('amount');
     $laserCutterMoneySpent = $this->paymentRepository->getEquipmentFeePayments('laser')->sum('amount');
     return \View::make('payment_overview.index')->with(compact('balancePaidIn', 'balancePaidOut', 'balanceLiability', 'storageBoxLiability', 'doorKeyLiability', 'laserCutterInvestment', 'laserCutterMoneySpent'));
 }