src/Timer/Timer.php
public static function start($name = null)
    {
        if (null === $name) {
            static::$time = -static::getTime();
        } else {
            static::$times[$name] = -static::getTime();
        }
    }
public static function start($name = null)
    {
        if (null === $name) {
            static::$time = -static::getTime();
        } else {
            static::$times[$name] = -static::getTime();
        }
    }
Start time. If name is null, start global timer.

@param  string $name
@return void