Timer-Class for Testing speed of PHP-Scripts or find speed brake

Timer.php

<?php

    /**
     * Timer vor Testing PHP-Scripts
     * @copyright   tomasiMEDIA 2013
     * @author      Dominik Tomasi
     * @date        09.12.13
     * 
     * usage:
     * Timer::start();
     * 
     * somewhere in your Code do -> Timer::newStop('nameOfEntry');
     * 
     * at end of script do -> Timer::getResults(); 
     * or as String -> Timer::getResultsAsString();
     * 
     */


class Timer
{
    /**
     * StartTime
     * @var null
     */
    private static $startTime = null;

    /**
     * Array of Timers
     * @var array
     */
    private static $arrTimers = array();

    /**
     * Get Time
     * @return float
     */
    private static function getmicrotime()
    {
        list($usec, $sec) = explode(" ", microtime());
        return ((float)$usec + (float)$sec);
    }

    /**
     * Start Timer
     */
    public static function start()
    {
        self::$startTime = self::getmicrotime();
    }


    /**
     * Stop a Time an give a Name
     * @param $strName
     * @throws \ErrorException
     */
    public static function newStop($strName)
    {
        if (is_null(self::$startTime))
        {
            throw new \ErrorException('Timer: start method not called !');
        }

        self::$arrTimers[$strName] = round((self::getmicrotime() - self::$startTime), 4);
    }

    /**
     * Get Timer Results as Array
     * @return array
     */
    public static function getResults()
    {
        return self::$arrTimers;
    }

    /**
     * Return the Timer-Array as printable String
     * @return string
     */
    public static function getResultAsString()
    {
        ob_start();
        var_dump(self::$arrTimers);
        $result = ob_get_clean();
        return $result;
    }
}