code: private function runtimeVals()
      {
          $vals = $this->debug->getData('runtime');
          if (!$vals) {
              $vals = array(
                  'memoryPeakUsage' => \memory_get_peak_usage(true),
                  'memoryLimit' => $this->debug->utilities->memoryLimit(),
                  'runtime' => $this->debug->timeEnd('debugInit', true),
              );
              $this->debug->setData('runtime', $vals);
          }
          return $vals;
      }
docs: Get/store values such as runtime & peak memory usage
  
  @return array