code: public function setBuiltInFormatCode($pValue)
      {
          if ($this->isSupervisor) {
              $styleArray = $this->getStyleArray(['formatCode' => self::builtInFormatCode($pValue)]);
              $this->getActiveSheet()->getStyle($this->getSelectedCells())->applyFromArray($styleArray);
          } else {
              $this->builtInFormatCode = $pValue;
              $this->formatCode = self::builtInFormatCode($pValue);
          }
  
          return $this;
      }
docs: Set Built-In Format Code.
  
  @param int $pValue
  
  @return NumberFormat