models/classes/runner/time/QtiTimeConstraint.php
private function durationToMs($duration)
    {
        if(!is_null($duration) && $duration instanceof QtiDuration){
            return TestRunnerUtils::getDurationWithMicroseconds($duration);
        }
        return false;
    }
private function durationToMs($duration)
    {
        if(!is_null($duration) && $duration instanceof QtiDuration){
            return TestRunnerUtils::getDurationWithMicroseconds($duration);
        }
        return false;
    }
Converts a duration to milliseconds
@param QtiDuration|null $duration the duration to convert
@return int|false the duration in ms or false if none