i have an assignment to write a hotel booking system in java

i have to write this class

"The Booking class brings together all the details for a booking into a single object. When creating a Booking object, it is vital that:

* The room availability has previously been checked.
* A HotelDate object for the start date of the booking has been created.
* A GuestData object containing the appropriate names has been created.

You are required to write the Booking class from scratch. It has the following attributes:

* private HotelDate startDate
The first date of the booking
* private int numberOfDays
The length of the booking period in days. Eg 7 for a booking of 1 week.
* private GuestData guests
The details of the guest(s) making the booking
* private Room room
The room to be occupied.

but i dont understand where i create the HotelData and guestData objects
is it in the contructor or before?