public Borrowing(int id, Magazine magazine, Friend friend, DateTime borrowingDate)
{
if (!IsValidMagazine(magazine))
{
throw new ArgumentException("Magazine property cannot be set instantiated as a null value.");
}
if (!isValidFriend(friend))
{
throw new ArgumentException("Friend property cannot be set instantiated as a null value.");
}
if (!IsValidDateTime(borrowingDate))
{
throw new ArgumentException("BorrowingDate property cannot be set as a date from the future.");
}
this.id = id;
this.magazine = magazine;
this.friend = friend;
this.borrowingDate = borrowingDate;
}
private bool IsValidMagazine(Magazine magazine)
{
return(magazine != null);
}