code: private function getBind()
      {
          [$dsBegin, $treeType] = $this->extractInput();
          $calcId = $this->getCalcId($dsBegin, $treeType);
          $bind = [
              QGrid::BND_CALC_ID => $calcId
          ];
          return $bind;
      }
docs: Analyze HTTP request, load data from DB to compose bind array with parameters for grid query.
  
  @return array