B25.TimeSlotFinder.Context context = new B25.TimeSlotFinder.Context();

// the time slot context defines what the resulting series of slots should look like
context.timeSlotContext = new B25.TimeSlotGenerator.Context();
context.timeSlotContext.startOfRange = System.now();
context.timeSlotContext.endOfRange = System.now().addHours(2);
context.timeSlotContext.duration = 60;
context.timeSlotContext.interval = 15;
// specify all the potential resource ids
// NOTE: replace these with resource ids that exist in your org!
context.fieldIds = new Map<String, List<Id>>{
	'B25__Resource__c' => new List<Id>{'a0eJX000000hnL7YAI', 'a0eJX000000hnL8YAI'}
};

// call the method and do something with the result
B25.TimeSlotFinder.Result result = B25.TimeSlotFinder.findTimeSlots(context);
for (B25.TimeSlot timeSlot : result.timeSlots) {
	System.debug('available time slot from ' + timeSlot.startDatetime
		+ ' until ' + timeSlot.endDatetime);
	B25.TimeSlotWithReservations timeSlotWithReservations = (B25.TimeSlotWithReservations) timeSlot;
	System.debug(timeSlotWithReservations.reservations);
}