public function getPeakMemoryUsage()
    {
        return isset($this->ends['pmu']) && isset($this->starts['pmu']) ? $this->ends['pmu'] - $this->starts['pmu'] : 0;
    }
public function getPeakMemoryUsage()
    {
        return isset($this->ends['pmu']) && isset($this->starts['pmu']) ? $this->ends['pmu'] - $this->starts['pmu'] : 0;
    }
Returns the peak memory usage in bytes.

@return int