code: public function getConsumerId($generate = false)
      {
          if (is_null($this->consumerId) && $generate) {
              $this->consumerId = $this->generateGuid();
          }
  
          return $this->consumerId;
      }
docs: Get the TransactionFlowLink Consumer ID
  
  @param bool $generate Whether to generate a consumer ID
  @return string|null