code: private function groupPvTrans($transData)
      {
          $result = [];
          foreach ($transData as $one) {
              $debitAccId = $one->get(DTrans::A_ACC_ID_DEBIT);
              $creditAccId = $one->get(DTrans::A_ACC_ID_CREDIT);
              $value = $one->get(DTrans::A_AMOUNT);
              if (isset($result[$debitAccId])) {
                  $result[$debitAccId] -= $value;
              } else {
                  $result[$debitAccId] = -$value;
              }
              if (isset($result[$creditAccId])) {
                  $result[$creditAccId] += $value;
              } else {
                  $result[$creditAccId] = $value;
              }
          }
          return $result;
      }
docs: Collect PV transitions on accounts and get PV turnover for period.
  
  @param \Praxigento\BonusHybrid\Service\Calc\PvWriteOff\A\Data\Trans[] $transData
  @return array [accId => pvTurnover]