code: private function getCalcData()
      {
          /* get period & calc data (first calc in the chain) */
          $ctx = new \Praxigento\Core\Data();
          $ctx->set($this->servPeriodGetBasis::CTX_IN_CALC_CODE, Cfg::CODE_TYPE_CALC_BONUS_SIGN_UP_DEBIT);
          $ctx->set($this->servPeriodGetBasis::CTX_IN_ASSET_TYPE_CODE, Cfg::CODE_TYPE_ASSET_PV);
          $ctx->set($this->servPeriodGetBasis::CTX_IN_PERIOD_TYPE, \Praxigento\Core\Api\Helper\Period::TYPE_MONTH);
          $this->servPeriodGetBasis->exec($ctx);
          $periodData = $ctx->get($this->servPeriodGetBasis::CTX_OUT_PERIOD_DATA);
          $calcData = $ctx->get($this->servPeriodGetBasis::CTX_OUT_CALC_DATA);
          $result = [$periodData, $calcData];
          return $result;
      }
docs: Get data for dependent calculation.
  
  @return array [$periodData, $calcData]
  @throws \Exception