src/Debug/MethodProfile.php
protected function popStack()
    {
        $stackInfo = \array_pop($this->funcStack);
        $funcPopped = $stackInfo['function'];
        $timeElapsed = \microtime(true) - $stackInfo['tsStart'];
        $this->data[$funcPopped]['ownTime'] += $timeElapsed - $stackInfo['subTime'];
        $this->data[$funcPopped]['totalTime'] += $timeElapsed;
        if ($this->data[$funcPopped]['calls'] === 0) {
            $this->data[$funcPopped]['calls'] ++;
        }
        if ($this->funcStack) {
            $this->funcStack[\count($this->funcStack)-1]['subTime'] += $timeElapsed;
        }
        return $stackInfo['function'];
    }
protected function popStack()
    {
        $stackInfo = \array_pop($this->funcStack);
        $funcPopped = $stackInfo['function'];
        $timeElapsed = \microtime(true) - $stackInfo['tsStart'];
        $this->data[$funcPopped]['ownTime'] += $timeElapsed - $stackInfo['subTime'];
        $this->data[$funcPopped]['totalTime'] += $timeElapsed;
        if ($this->data[$funcPopped]['calls'] === 0) {
            $this->data[$funcPopped]['calls'] ++;
        }
        if ($this->funcStack) {
            $this->funcStack[\count($this->funcStack)-1]['subTime'] += $timeElapsed;
        }
        return $stackInfo['function'];
    }
Remove function from stack and add time to profile

@return string name of popped function