src/Debug/Internal.php
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;
    }
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;
    }
Get/store values such as runtime & peak memory usage

@return array