public class Timer {
    double startTime;
    double endTime;

    public Timer() {
        startTime = System.currentTimeMillis();
    }

    public Timer(double s) {
        startTime = s;
    }

    public void setEndTime() {
        endTime = System.currentTimeMillis();
    }

    public void setEndTime(double e) {
        endTime = e;
    }

    public void setStartTime() {
        startTime = System.currentTimeMillis();
    }

    public void setStartTime(double s) {
        startTime = s;
    }

    public double calcElapsedTime() {
        return endTime - startTime;
    }
}