java_9_before

double getFlowBetween (Date start, Date end) {
    double result = 0;
    Enumeration e = entries.elements();
    while (e.hasMoreElements()) {
        Entry each = (Entry) e.nextElement();
        if (each.getDate().equals(start) || each.getDate().equals(end) ||
            (each.getDate().after(start) && each.getDate().before(end))){
            result += each.getValue();
        }
    }
    return result;
}