private static int extractDataOfInterest(RentalZone zone, DataOfInterest what) {
switch (what) {
case STARTS:
case INTERPOLATION:
return zone.getRentalStarts();
case ENDS:
return zone.getRentalEnds();
case SINKS:
int sinks = zone.getRentalEnds() - zone.getRentalStarts();
if (sinks < 0) return -1;
return sinks;
case SOURCES:
int source = zone.getRentalStarts() - zone.getRentalEnds();
if (source < 0) return -1;
return source;
default:
return -1;
}
}
