public int getTotalDuration() {
        int d = this.duration;
        if (d < 0) {
            d = Minutes.minutesBetween(this.start, this.end).getMinutes();
            d = Math.abs(d);
            this.duration = d;
        }
        return d;
    }
public int getTotalDuration ( ) { int d = this . duration ; if ( d < 0 ) { d = Minutes . minutesBetween ( this . start , this . end ) . getMinutes ( ) ; d = Math . abs ( d ) ; this . duration = d ; } return d ; }
@return Minutes between {@link #getStart()} and {@link #getEnd()}