code: public function onShutdown()
      {
          $this->runtimeVals();
          if ($this->testEmailLog()) {
              $this->emailLog();
          }
          if (!$this->debug->getData('outputSent')) {
              echo $this->debug->output();
          }
          return;
      }
docs: Email Log if emailLog is 'always' or 'onError'
  output log if not already output
  
  @return void